<PAGE>   1
                                                                       CONFORMED

                    SECURITIES AND EXCHANGE COMMISSION
                          Washington, D.C. 20549

                                FORM 10-K

                              ANNUAL REPORT
                     PURSUANT TO SECTION 13 OR 15(d)
                  OF THE SECURITIES EXCHANGE ACT OF 1934

               For the fiscal year ended December 31, 1998

                       Commission file number 1-228

                            ZEMEX CORPORATION
          (Exact name of registrant as specified in its charter)

           CANADA                                   NONE
      (State or other                         (I.R.S. employer
      jurisdiction of                      identification number)
      incorporation or
       organization)


        CANADA TRUST TOWER, BCE PLACE, 161 BAY STREET, SUITE 3750
                     TORONTO, ONTARIO, CANADA M5J 2S1
                              (416) 365-8080
           (Address, including zip code, and telephone number,
    including area code, of registrant's principal executive offices)

        SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT

Toronto Stock Exchange and 
New York Stock Exchange                              Common Stock, no par value


Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange
Act of 1934 during the preceding twelve months (or for such shorter
period that the registrant was required to file such reports), and (2)
has been subject to such filing requirements for the past 90 days.

                               YES  X     NO

Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not be
contained, to the best of the registrant's knowledge, in definitive proxy
or information statements incorporated by reference in Part III of this
Form 10-K or any amendment to this Form 10-K. |X|

The aggregate market value of the registrant's voting stock (common
shares, no par value) held by non-affiliates as of March 18, 1999 (based
on the closing sale price of $5.125 on the New York Stock Exchange) was
$23,812,749.

As of March 18, 1999, 8,707,796 shares of the registrant's common shares,
no par value, were outstanding.

                   DOCUMENTS INCORPORATED BY REFERENCE

Annual Report to Shareholders for the Year Ended 
December 31, 1998                                                       Part II

Definitive Proxy Statement filed with the Commission 
pursuant to Regulation 14A with respect to the 
1999 Annual Meeting of Shareholders                                     Part III


<PAGE>   2



                                FORM 10-K
                              ANNUAL REPORT

                            TABLE OF CONTENTS
                                   AND
                          CROSS-REFERENCE SHEET


                                  PART I

                                                                            PAGE

Item 1.  Business............................................................ 1
Item 2.  Properties.......................................................... 8
Item 3.  Legal Proceedings................................................... 9
Item 4.  Submission of Matters to a Vote of Security Holders................. 9
Item 10. Executive and Other Officers of the Registrant(A)................... 9


                                 PART II

Item 5.  Market for Registrant's Common Equity and Related 
         Stockholder Matters(B).............................................. 9
Item 6.  Selected Financial Data(C).......................................... 9
Item 7.  Management's Discussion and Analysis of Financial Condition and
         Results of Operation(D)............................................. 9
Item 8.  Financial Statements and Supplementary Data(E) .................... 10
Item 9.  Changes in and Disagreements with Accountants on Accounting and
         Financial Disclosure............................................... 10


                                 PART III

Item 10. Directors and Executive Officers of the Registrant(F)............... *
Item 11. Executive Compensation(F)........................................... *
Item 12. Security Ownership of Certain Beneficial Owners and Management(F)... *
Item 13. Certain Relationships and Related Transactions(F)................... *


                                 PART IV

Item 14. Exhibits, Financial Statement Schedules, and Reports on Form 8-K... 11



<PAGE>   3


--------------------------

(A)   Included in Part I, Item 1, pursuant to Instruction 3 of Item 401(b) 
      of Regulation S-K.

(B)   Information responsive to this Item is set forth on page 31 of the
      registrant's Annual Report to Shareholders for the year ended
      December 31, 1998 (the "Annual Report to Shareholders") and is
      incorporated herein by reference. The Annual Report to Shareholders
      is included as Exhibit 13 to this Form 10-K Annual Report. The
      Annual Report to Shareholders, except for those portions thereof
      which are expressly incorporated by reference herein, is furnished
      for the information of the Commission and is not to be deemed
      "filed" as part of this Form 10-K report.

(C)   Information responsive to this Item is set forth on page 62 of the
      Annual Report to Shareholders and is incorporated herein by
      reference.

(D)   Information responsive to this Item is set forth on pages 23
      through 31 of the Annual Report to Shareholders and is incorporated
      herein by reference.

(E)   Financial statements responsive to this Item are set forth on pages
      32 through 61 of the Annual Report to Shareholders and are
      incorporated herein by reference. The Supplementary Schedule
      required by this Item is set forth on page S-1 of this Form 10-K
      Annual Report.

(F)   Information responsive to these Items is set forth in the
      registrant's definitive proxy statement to be filed with the
      Commission pursuant to Regulation 14A and in the Annual Report to
      Shareholders on page 52 (Note 14) and is incorporated herein by
      reference.


<PAGE>   4




                                  PART I


ITEM 1.  BUSINESS

GENERAL

Zemex Corporation (the "Corporation" or "Zemex"), a company subject to
the laws of the Canada Business Corporations Act, is a niche producer of
specialty materials and products for use in a variety of industrial
applications. Zemex operates through three major divisions: (i)
industrial minerals, (ii) metal powders, and (iii) aluminum recycling.
Its major products include feldspar, feldspathic minerals, kaolin, sand,
mica, talc, ferrous and non ferrous powders, and aluminum dross
derivatives. Zemex currently operates eighteen plants throughout Canada
and the United States.

Originally, Zemex was incorporated under the laws of the State of Maine
in 1907 and was known as Yukon Gold Corporation. At its annual meeting of
shareholders on May 20, 1938, a resolution was passed to change its name
to Yukon-Pacific Mining Corporation. On November 8, 1939, Zemex
reorganized, incorporated under the laws of the State of Delaware, and
changed its name to Pacific Tin Consolidated Corporation. Also in 1939,
Zemex listed on the New York Stock Exchange. In 1985, Zemex changed its
name to its current form and reincorporated under the laws of the State
of Delaware as the successor to Pacific Tin Corporation. Effective
January 21, 1999 Zemex completed a reincorporation merger and
reincorporated under the Canada Business Corporations Act.

INDUSTRIAL MINERALS

The Corporation's industrial minerals is comprised of The Feldspar
Corporation ("TFC"), Suzorite Mica Products Inc. ("Suzorite"), Suzorite
Mineral Products, Inc. ("SMP"), Zemex Fabi-Benwood, LLC, Zemex Industrial
Minerals, Inc. and Zemex Mica Corporation (collectively, "Zemex
Industrial Minerals" or "ZIM"). Each of these companies is a wholly-owned
subsidiary of Zemex except for Zemex Fabi-Benwood, LLC of which Zemex
owns 60%.

TFC has mining and processing facilities in Edgar, Florida; Monticello,
Georgia; and Spruce Pine, North Carolina. Using traditional methods, TFC
mines sodium feldspar from two different ore deposits in the Spruce Pine
area; potassium feldspar is mined from two deposits close to the
Monticello plant. TFC's kaolin and sand products are recovered by
dredging and wet separation at the Edgar property. All mined and
recovered products are subjected to standard and proprietary milling and
drying techniques.

TFC produces numerous products at its operating plants, including sodium
and potassium feldspar, silica, low iron sand, muscovite mica and kaolin
clay. Feldspathic materials are key ingredients for the ceramic industry,
and are incorporated into the production of ceramic floor and wall tiles,
dinnerware, plumbing fixtures, glazes and electrical insulators. TFC
supplies its products primarily to the glass and ceramics industries.
Feldspar and certain grades of industrial sand are also used to
manufacture bottles, jars, and other glass containers, fibreglass, paints
and plastics, and television picture tubes. Industrial sand is used for
filter, filler, beach sand, blasting and concrete applications. TFC also
produces a low iron sand product for use in highly specialized glass
applications.

Suzorite mines phlogopite mica in an open pit mining operation in Suzor
Township, Quebec, Canada, approximately 300 kilometres north of Montreal,
Quebec. The ore is mined by standard open pit methods and delivered to a
siding for transportation by rail to the processing plant, which is
located in Boucherville, 


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<PAGE>   5

Quebec, a suburb of Montreal. Because of its distinct thermal stability
advantage over competitive materials, phlogopite mica is used to impart
rigidity in technological and high temperature plastic applications.
Suzorite's phlogopite mica is used as a partial or complete substitute
for asbestos in fire retardation. It is also used in friction materials,
oil well drilling needs, caulking and molding compounds, coatings,
plasters and plastics. The principal markets served by Suzorite are the
automobile, construction and oil drilling industries. These products are
marketed under the trade names Suzorite Mica and Suzorex.

SMP produces talc and other minerals at Natural Bridge, New York; Murphy,
North Carolina; Van Horn, Texas; and Benwood, West Virginia. SMP
purchases raw materials for conversion and processing at its plant in
Natural Bridge and processes products directed primarily to the cosmetic
and pharmaceutical industries. The production facility in Van Horn
processes ores mined in proximity to the plant for the coatings, plastics
and ceramics industries. The Benwood operation processes a wide range of
talc products from imported raw materials for ultimate use in the
plastics industry. The Murphy plant produces, from purchased sources,
baryte products, primarily for the oil drilling and coatings industries.

In late 1996, SMP completed the installation of a new mill at its
facility in Benwood, West Virginia. This new fine grind milling capacity
is part of SMP's strategy to develop a niche in the talc marketplace by
offering very finely divided high purity talc products to industrial
markets. SMP believes that it is one of the few talc producers in North
America to produce products of this purity and fineness. The products
find application in performance plastics, high end coatings and other
markets. With the addition of these new fine grind products, Benwood has
the ability to produce a broad spectrum of high purity talc products.

In January 1998, the Corporation acquired a muscovite mica producer in
the Spruce Pine, North Carolina area. The facilities acquired in the
purchase operate under the name Zemex Mica Corporation ("ZMC") and are
located close to TFC's feldspar plant where by-product muscovite mica is
produced. This acquisition enhances the Corporation's position as a major
mica supplier.

In February 1998, Industria Mineraria Fabi S.r.l. ("Fabi"), a leading
European talc producer, became an investor in the Corporation's talc
facility located in Benwood, West Virginia by acquiring a 40% interest in
a new limited liability company, Zemex Fabi-Benwood, LLC. As part of the
transaction, Fabi paid $3.1 million and is providing access to its
technology and premium talc deposit in Australia. SMP manages the new
entity pursuant to an operating agreement.

Demand for Zemex's industrial minerals is related to the pace of the
general economy and, particularly, the residential and commercial
construction industries.

The Corporation's industrial minerals sales were $44.8 million in 1998,
compared with $43.4 million in 1997 and $40.5 million in 1996. This
business segment reported operating income of $5.8 million in 1998, $6.5
million in 1997 and $2.8 million in 1996.

During 1998, considerable efforts were directed to product development,
marketing, capital expansion projects and product quality improvement.
The Corporation expects these efforts will bear fruit in the future.

Capital expenditures were $8.3 million in 1998 compared to $9.9 million
in 1997 and $11.9 million in 1996. Major capital spending in 1998
included the retrofitting of the recently acquired muscovite mica
operation in Spruce Pine, North Carolina.


                                    2
<PAGE>   6

METAL POWDERS

The metal powders division consists of two wholly-owned subsidiaries,
Pyron Corporation and Pyron Metal Powders, Inc. (together, "Pyron").
Pyron operates plants located in Niagara Falls, New York; St. Marys,
Pennsylvania; and Greenback and Maryville, Tennessee. Pyron's major
products include iron, steel, copper, copper alloy powders and manganese
sulfide. The primary applications of metal powders are in the fabrication
of precision metal parts using powder metallurgy and in the friction
industry. Powder metallurgy is an efficient, economical process for the
production of complex components used in the automotive, farm, garden and
lawn equipment, and business machine industries. Key features of powder
metallurgy technology are low scrap ratios and lower production costs
when compared to other conventional metal working processes.

In recent years, metal powder use in the friction industry and,
particularly, in automotive and rail braking systems has grown rapidly as
a replacement for asbestos, achieving better performance and improved
environmental and health conditions. Metal powders are also used in the
production of welding rods, for cutting and scarfing of steel ingots and
billets, for the inspection of oil field pipe and tubing, and in food
supplements.

In 1995, Pyron completed construction of a blending plant in St. Marys,
Pennsylvania. Through its blending facility, Pyron is able to provide
custom pre-packaged powders and just-in-time service to its customers.

In late 1996, Pyron completed construction of a facility for the
production of manganese sulfide at its Greenback, Tennessee location.
Pyron's new product, Manganese Sulfide Plus (MnS+TM), was developed in
Pyron's laboratory and is used as an additive by the powder metallurgical
industry to enhance tool life and aid in machinability. Customer demand
for MnS+TM has been strong and, as a result, the capacity of the facility
was doubled in 1997 to satisfy orders. Manganese sulfide is a natural
complement to Pyron's core ferrous and non-ferrous businesses as it
further broadens Pyron's expansive product line.

Sales for the metal powders group increased to $35.6 million in 1998 from
$33.9 million in 1997. Sales were $31.7 million in 1996. The increase
from 1997 to 1998 was due to higher volumes of ferrous and non ferrous
metal powders. During the same interval, operating income increased from
$2.4 million in 1997 to $4.0 million in 1998. Operating income was $2.4
million in 1996. Management anticipates improved margins in this segment
in 1999 as a result of new products, higher metal powder production,
continuing cost reductions, and efficiency improvement programs.

Capital expenditures for the metal powders group were $2.1 million in
1998 as compared to $1.3 million in 1997 and $2.2 million in 1996. The
1998 expenditures were primarily directed towards retrofitting a furnace
and general sustaining capital requirements. In 1999, capital
expenditures are anticipated to be $3.7 million.

ALUMINUM RECYCLING

Zemex's aluminum recycling group is composed of Alumitech, Inc.,
Alumitech of Cleveland, Inc., Alumitech of Wabash, Inc., ETS Schaefer
Corporation and AWT Properties, Inc. (collectively, "Alumitech"), all of
which are direct or indirect wholly-owned subsidiaries.

Zemex acquired its initial interest in Alumitech in 1994 and increased
its ownership to 100% in 1995. Alumitech now has three facilities:
aluminum dross reprocessing plants in Cleveland, Ohio and Wabash,


                                    3
<PAGE>   7


Indiana, and a heat containment fabrication plant in Macedonia, Ohio. Its
administrative office is in Streetsboro, Ohio.

Alumitech is an aluminum dross processor that has developed and patented
proprietary technology to recycle secondary aluminum drosses into
industrial feedstock components, eliminating the necessity for landfill.
Aluminum dross is the waste by-product produced by primary and secondary
aluminum smelters. Secondary dross, which has a high salt content, forms
the primary feedstock for Alumitech's process. Conventional dross
processors simply recover aluminum metal and some oxides and send the
residue to landfill. Using its patented process, Alumitech has the
ability to separate the dross into its basic components: aluminum metal,
alumina and metal fines, salts and non-metallic product ("NMP") and
further refine the NMP for use as a feedstock for the production of
calcium aluminate, refractory ceramic fibre and other commercially
acceptable products. Currently, competitive processes landfill anywhere
from 40%-75% of the volume of dross received, whereas Alumitech's
recycling process has the ability to virtually eliminate the need for
landfill. Alumitech is considered the industry leader in the development
of alternative uses for NMP. Alumitech's patents on its technology to
process NMP have a remaining life of approximately 12 years.

In February 1997, Alumitech, through its wholly-owned subsidiary,
Engineered Thermal Systems, Inc., acquired the assets of Schaefer
Brothers, Inc., a small regional manufacturer of ceramic fibre-based heat
containment systems located in Medina, Ohio. The Schaefer Brothers
business was merged with Engineered Thermal Systems, Inc., also a
manufacturer of ceramic fibre-based heat containment systems, to form ETS
Schaefer Corporation.

In June 1998, Alumitech acquired 100% of the issued and outstanding
shares of Alumitech of Wabash, Inc. (previously known as S&R Enterprises,
Inc.), a Wabash, Indiana based aluminum dross processor. This acquisition
provides Alumitech with additional metal melting capacity and the
opportunity to expand its NMP processing capability.

Sales for the aluminum recycling group increased to $23.5 million in 1998
from $19.9 million in 1997. Sales were $14.2 million in 1996. The
increase from 1997 to 1998 was due to higher volumes and the acquisition
of Alumitech of Wabash, Inc. During the same interval, operating income
increased from $1.9 million in 1997 to $2.9 million in 1998. Operating
income was $0.2 million in 1996. Management anticipates improved margins
in this segment in 1999 as a result of new products, continuing cost
reductions, and efficiency improvement programs.

Capital expenditures for the metal products group were $10.1 million in
1998 as compared to $5.3 million in 1997 and $2.3 million in 1996. The
1998 expenditures were primarily directed to the construction and
commercialization of a new NMP processing facility at the Cleveland plant
and the acquisition of the aluminum dross recycling operation in Wabash,
Indiana. In 1999, capital expenditures are anticipated to be $3.9
million.

RAW MATERIALS AND OTHER REQUIREMENTS

In recent years, the Corporation has not experienced any substantial
difficulty in satisfying the raw materials requirements for its metal
products operations, which is the segment that consumes, rather than
supplies, raw materials. However, no assurance can be given that any
shortages of these or other necessary materials or equipment will not
develop or that increased prices will not adversely affect the
Corporation's business in the future.



                                    4
<PAGE>   8

SEASONALITY

The efficiency and productivity of the Corporation's operations can be
affected by unusually severe weather conditions. During the winter of
1998, there were minor production outages at the Corporation's operating
facilities in North Carolina, New York, Ohio and Quebec due to inclement
weather, but they were not significant enough to materially affect 1998
operating results.

COMPETITION

All of the Corporation's products are sold in highly competitive markets
which are influenced by price, performance, customer location, service,
competition, material substitution and general economic conditions. The
Corporation competes with other companies active in industrial minerals
and metal products. No material part of the Corporation's business is
dependent upon any single customer, or upon very few customers, the loss
of any one of which could have a material adverse impact on the
Corporation.

Industrial mineral prices generally are not subject to the price
fluctuations typical of commodity metals. Demand for industrial minerals
is primarily related to general economic conditions, particularly in the
automotive, housing and construction industries. Markets for industrial
mineral products are sensitive not only to service, product performance,
and price, but also to competitive pressures and transportation costs. In
the United States, there are three major feldspathic mineral producers,
including the Corporation. The Corporation is the only North American
producer of phlogopite mica and one of many talc producers.

The Corporation is one of five North American producers of metal powders.
The market for metal powders is affected primarily by product
performance, consistency of quality and price. To some extent,
competition in the metal powder industry is affected by imports of
finished metal powder parts. Product prices over the last several years
have been strongly influenced by available capacity. Demand for metal
powders is a function of general economic conditions, particularly in the
automotive market.

There are numerous aluminum dross processors in the United States,
however, only Alumitech has patented technology which enables it to
process aluminum dross without the necessity for landfill. While the
Corporation competes for the supply of aluminum dross with a number of
other dross processors, the major factor affecting the supply of dross is
the level of activity of the aluminum smelting industry. In addition, as
aluminum is one of the products of aluminum dross reprocessing, commodity
price fluctuations of aluminum may have an impact on the earnings of the
Corporation.

RESEARCH AND DEVELOPMENT

The Corporation carries on an active program of product development and
improvement. Research and development expense was $0.6 million in 1998,
$1.0 million in 1997 and $0.6 million in 1996.

Financial information about industry segments is set forth on pages 53 to
55 of the Annual Report to Shareholders and is incorporated herein by
reference.

ENVIRONMENTAL CONSIDERATIONS

Laws and regulations currently in force which do or may affect the
Corporation's domestic operations include the Federal Clean Air Act of
1970, the National Environmental Policy Act of 1969, the Solid Waste
Disposal Act (including the Resource Conservation and Recovery Act of
1976), the Toxic Substances Control Act, CERCLA (superfund) and
regulations under these Acts, the environmental 


                                    5
<PAGE>   9

protection regulations of various governmental agencies (e.g. the Bureau
of Land Management Surface Management Regulations, Forest Service
Regulations, and Department of Transportation Regulations), laws and
regulations with respect to permitting of land use, various state and
local laws and regulations concerned with zoning, mining techniques,
reclamation of mined lands, air and water pollution and solid waste
disposal. Currently, the Corporation is not aware of any materially
adverse environmental problems or issues.

EMPLOYEES

The approximate number of employees in the Corporation as of December 31,
1998 is set forth below:

<TABLE>
<S>                                                     <C>
        Industrial Minerals                             325
        Metal Powders                                   172
        Aluminum Recycling                              187
        Corporate                                         7
                                                     -------
        Total                                           691
                                                     =======
</TABLE>

Approximately 60 employees at the Corporation's metal powder operations
in Niagara Falls, New York, are covered by a three-year collective
bargaining agreement, which expires April 15, 2001. At the ferrous metal
powder facilities in Tennessee, approximately 41 employees are covered by
a four-year agreement, which expires February 28, 2002.

Approximately 20 employees at Suzorite are covered by a three-year
collective bargaining agreement that expires December 13, 1999.

At Alumitech, approximately 28 employees are covered by two collective
bargaining agreements, one agreement expiring April 30, 1999 and one
agreement expiring December 31, 1999.

On March 26, 1998, the hourly employees at TFC's plant in Spruce Pine,
North Carolina voted in favour of union certification. Contract
negotiations have commenced. The Corporation considers its labour
relations to be good.

FOREIGN OPERATIONS

Most of the Corporation's operations are located in the United States.
One is located in Canada, a country whose institutions and governmental
policies are generally similar to those of the United States. Although
there can be no assurance as to future conditions, the Corporation has
experienced no political activities, social upheavals, currency
restrictions or similar factors which have had any material adverse
effect to date on the results of its operations or financial condition.

EXPORT SALES

The Corporation's industrial minerals, metal powders and aluminum
recycling operations sell their products internationally to a wide
variety of customers including the ceramics, glass and powder metallurgy
industries. Export sales in these three segments were less than 9% of
total sales.


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<PAGE>   10

EXECUTIVE AND OTHER OFFICERS OF THE REGISTRANT

<TABLE>
<CAPTION>
                                                                                                    SERVED IN
OFFICER                             POSITION                                      AGE             POSITION SINCE

<S>                                 <C>                                          <C>                  <C> 
Peter Lawson-Johnston               Chairman of the Board of Directors            72                   1975

Richard L. Lister                   President and Chief Executive Officer         60                   1993

Allen J. Palmiere                   Vice President, Chief Financial Officer       46                   1993
                                    and Assistant Secretary

Peter J. Goodwin                    President, Industrial Minerals                48                   1994


Terrance J. Hogan                   President, Alumitech, Inc.                    43                   1995

George E. Gillespie                 President, Metal Powders                      56                   1997

Patricia K. Moran                   Corporate Secretary and                       33                   1997
                                    Assistant Treasurer
</TABLE>

There are no family relationships between the officers listed above. The
term of office of each executive officer is until his/her respective
successor is elected and has qualified, or until his/her death,
resignation or removal. Officers are elected or appointed by the board of
directors annually at its first meeting following the annual meeting of
shareholders. The following are the current officers of the Corporation
and a description of their business activities if less than five years in
their present position.

Mr. Goodwin joined the Corporation in August 1994 and became President of
the Corporation's talc operations in December 1994. From May 1993 to
August 1994, Mr. Goodwin was a self-employed consultant. Mr. Goodwin was
President and Chief Executive Officer of Miller and Co. from August 1990
to May 1993.

Mr. Hogan became President of Alumitech, Inc. in May 1995. Prior to
becoming President, Mr. Hogan was Chief Operating Officer of Alumitech's
subsidiary, Aluminum Waste Technology, Inc., from December 1992 to May
1995.

Mr. Gillespie became President of the Metal Powders Group in April 1997.
Prior to joining the Corporation, Mr. Gillespie was Chairman of the
Operating Committee for three divisions of The Carborundum Company in
1996. Mr. Gillespie was Vice-President Refractories from 1993 to 1996 for
The Carborundum Company.

Ms. Moran assumed the duties of Corporate Secretary and Assistant
Treasurer in May 1997. Prior to that time Ms. Moran served as Assistant
Secretary-Treasurer since February 1995. Ms. Moran has been with the
Corporation since 1993.



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<PAGE>   11

CAUTIONARY "SAFE HARBOR" STATEMENT UNDER THE
UNITED STATES PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995

With the exception of historical matters, the matters discussed in this
report are forward looking statements that involve risks and
uncertainties that could cause actual results to differ materially from
targeted or projected results. Factors that could cause actual results to
differ materially include, among others, fluctuations in aluminum prices,
problems regarding unanticipated competition, processing, access and
transportation of supplies, availability of materials and equipment,
force majeure events, the failure of plant equipment or processes to
operate in accordance with specifications or expectations, accidents,
labor relations, delays in start-up dates, environmental costs and risks,
the outcome of acquisition negotiations and general domestic and
international economic and political conditions, as well as other factors
described herein or in the Corporation's filings with the Commission.
Many of these factors are beyond the Corporation's ability to predict or
control. Readers are cautioned not to put undue reliance on forward
looking statements.

ITEM 2.  PROPERTIES

The industrial minerals segment has operations and mines in Edgar,
Florida; Monticello, Georgia; Boucherville, Quebec; Suzor Township,
Quebec; Natural Bridge, New York; Murphy, North Carolina; Spruce Pine,
North Carolina; Van Horn, Texas; and Benwood, West Virginia. This segment
owns approximately 391,500 square feet of office and plant floor space.
As well, the 60% owned processing facility in Benwood, West Virginia has
approximately twelve acres of land. In 1996, The Feldspar Corporation
purchased 655 acres which contain, at minimum, 20 years additional ore
resources for its Spruce Pine, North Carolina facility. The mineral
deposits currently operated by the industrial minerals segment are
estimated by the Corporation to be at least 25 years, except in the case
of the mica mine in Suzor Township where resources are estimated to be in
excess of 100 years. All of the Corporation's mining properties are
either owned or leased, with the leases expiring from 1999 to 2018.

The metal powders group has operations in Niagara Falls, New York; St.
Marys, Pennsylvania; Greenback, and Maryville, Tennessee. At its facility
in Niagara Falls, Pyron Corporation utilizes approximately 79,000 square
feet of office and plant floor space which it leases from the Niagara
County Industrial Development Agency as part of the Industrial
Development Revenue Bond issued in November 1989 to finance the
construction of an atomized steel powder plant. Lease payments are to be
sufficient to pay the debt service on the Industrial Development Revenue
Bond. The atomized plant utilizes approximately 16,000 square feet of
floor space and is adjacent to the existing facility. The blending plant
in St. Marys, Pennsylvania has 32,000 square feet of plant, office and
storage space and is situated on 3.4 acres of land. The Greenback
facility is situated on 27.5 acres of land of which 6 acres is actively
used in the operations. The Maryville facility is a leased facility which
utilizes approximately 23,000 square feet of office and plant floor
space.

The aluminum recycling group has operations in Cleveland, Ohio;
Macedonia, Ohio; Streetsboro, Ohio and Wabash, Indiana. The aluminum
dross processing plant in Cleveland, Ohio owns 6.1 acres and has
buildings totaling 51,000 square feet. The Streetsboro, Ohio operation
leases approximately 10% of a 36,000 square foot building, which it uses
primarily for office space. The recently built Macedonia facility
includes 72,210 square feet of plant of which 10,000 is designated office
space and is situated on 8 acres of land. The aluminum recycling
operation in Wabash, Indiana sits on approximately 25 acres of land and
has 73,300 square feet of plant and office space.

All facilities are maintained in good operating condition.


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<PAGE>   12


ITEM 3.  LEGAL PROCEEDINGS

During 1998, a civil action brought by Dryvit Systems, Inc. ("Dryvit") in
the State of Rhode Island captioned Dryvit Systems, Inc. v. The Feldspar
Corporation, Taggart Sand Products Corp., Surface Systems, Inc., The
Morie Company, Inc., Eriez Magnetics, Inc., and Law Engineering, Inc.,
C.A. No. KC 93-108, State of Rhode Island, Kent was settled. Dryvit
alleged that between approximately 1985 and 1990, that the sand it
purchased from TFC and other suppliers and utilized to manufacture
exterior insulation finishes for the exterior of buildings developed rust
stains because the sand contained pyrite and magnetic materials. The
Corporation's settlement costs were covered by its liability insurance.

In February 1999, the Corporation received notice that it was party to an
action captioned Marsha Fisher-Carrington Administratrix to the Estate of
Larry Carrington v. Aluminum Waste Technology, Inc. and Alumitech, Inc.,
et al., Court of Common Pleas, Cuyahoga County, Ohio, Case Number 373502.
The action arises from an accidental fatality that occurred at Alumitech
of Cleveland, Inc. in January 1997. The plaintiff is seeking damages on
the basis that the Corporation failed to provide a safe working area. The
Corporation is of the opinion that the claim is without merit; however,
should the plaintiff be successful, the Corporation believes its costs
will be covered by primary and excess liability insurance.


ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

None.


                                 PART II


ITEM 5.  MARKET FOR THE REGISTRANT'S COMMON
         EQUITY AND RELATED STOCKHOLDER MATTERS

Information responsive to this Item is set forth on page 31 of
registrant's Annual Report to Shareholders and is incorporated herein by
reference. The Annual Report to Shareholders is included as Exhibit 13 to
this Form 10-K Annual Report. The Annual Report to Shareholders, except
for those portions thereof which are expressly incorporated by reference
herein, is furnished for the information of the Commission and is not to
be deemed "filed" as part of this Form 10-K report.


ITEM 6.  SELECTED FINANCIAL DATA

Information responsive to this item is set forth on page 62 of the Annual
Report to Shareholders and is incorporated herein by reference.


ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF
         FINANCIAL CONDITION AND RESULTS OF OPERATION

Information responsive to this Item is set forth on pages 23 through 31
of the Annual Report to Shareholders and is incorporated herein by
reference.


                                    9
<PAGE>   13


ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Financial statements responsive to this Item are set forth on pages 32
through 61 of the Annual Report to Shareholders and are incorporated
herein by reference. The Supplementary Schedule required by this Item is
set forth on page S-1 of this Form 10-K Annual Report. See Item 14.


ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS
         ON ACCOUNTING AND FINANCIAL DISCLOSURE

None.


                                 PART III


ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

The information about the directors of the Corporation required by this
item is located in the Corporation's Proxy Statement for the 1999 Annual
Meeting to be filed within 120 days after the end of the fiscal year.
Information about the Executive Officers of the Corporation required by
this item appears in Part I, Item 1, of this Annual Report on Form 10-K*.


ITEM 11.  EXECUTIVE COMPENSATION

The information required by this item appears in the Corporation's Proxy
Statement for the 1999 Annual Meeting to be filed within 120 days after
the end of the fiscal year.


ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL
          OWNERS AND MANAGEMENT

The information required by this item appears in the Corporation's Proxy
Statement for the 1999 Annual Meeting to be filed within 120 days after
the end of the fiscal year.


ITEM 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

The information required by this item appears in the Corporation's Proxy
Statement for the 1999 Annual Meeting to be filed within 120 days after
the end of the fiscal year.



[FN]
--------
* Reference in this Annual Report on Form 10-K to material contained in
the Corporation's Proxy Statement for the 1999 Annual Meeting to be filed
within 120 days after the fiscal year incorporate such material into this
Report by reference.
</FN>



                                   10
<PAGE>   14



                                 PART IV


ITEM 14.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES,
          AND REPORTS ON FORM 8-K

1. Financial statements and independent auditors' report filed as part of
this report:

         (a)      Consolidated Balance Sheets at December 31, 1998 and
                  1997, which information is incorporated by reference
                  under Item 8 of this report;

         (b)      Consolidated Statements of Shareholders' Equity for the
                  three years ended December 31, 1998, which information
                  is incorporated by reference under Item 8 of this
                  report;

         (c)      Consolidated Statements of Income for the three years
                  ended December 31, 1998, which information is
                  incorporated by reference under Item 8 of this report;

         (d)      Consolidated Statements of Cash Flows for the three
                  years ended December 31, 1998, which information is
                  incorporated by reference under item 8 of this report;

         (e)      Notes to the Consolidated Financial Statements, which
                  information is incorporated by reference under Item 8
                  of this report;

         (f)      Independent Auditors' Report, which information is
                  incorporated by reference under Item 8 of this report;

         (g)      the Corporation's Current Report on Form 8-K dated
                  January 15, 1999 and filed with the Commission on
                  January 20, 1999; and

         (h)      the Corporation's Current Report on Form 8-K dated
                  January 21, 1999 and filed with the Commission on
                  January 22, 1999.

2. Financial statement schedules and independent auditors' report filed
as part of this report:

       SCHEDULE NUMBER                    DESCRIPTION

            --                            Report of Independent Auditors

       Schedule IX                        Valuation and Qualifying Accounts
                                          and Reserves (page S-1)

All other financial statements and schedules not listed have been omitted
since the required information is included in the consolidated financial
statements or the related notes thereto, or is not applicable or
required.

With the exception of the aforementioned financial statements and
schedule, and the information incorporated in Items 1 and 2 and Items 5
through 8, the 1998 Annual Report is not deemed to be filed as part of
this Annual Report on Form 10-K. Schedules not included in this Form 10-K
have been omitted because they are not applicable or the required
information is shown in the financial statements in the 1998 Annual
Report or notes related thereto.




                                   11
<PAGE>   15

3.  EXHIBITS

(3)(a)        Articles of Continuance (Incorporated by reference from
              Exhibit 3.1 of the Corporation's Registration Statement on
              Form S-4, Registration No. 333-65307, which was declared
              effective on December 10, 1998)

(3)(b)        Articles of Amendment to the Articles of Continuance
              (Incorporated by reference from Exhibit 3.2 of the
              Corporation's Registration Statement on Form S-4,
              Registration No. 333-65307, which was declared effective on
              December 10, 1998)

(3)(c)        By-Law No. 1 (Incorporated by reference from Exhibit 3.3 of
              the Corporation's Registration Statement on Form S-4,
              Registration No. 333-65307, which was declared effective on
              December 10, 1998)

(4)(a)        Indenture of Trust dated as of November 1, 1989 between
              Niagara County Industrial Development Agency and The Bank
              of New York as trustee for Pyron Corporation (Incorporated
              by reference from Exhibit (4)(a) of the Corporation's
              Annual Report on Form 10-K filed March 31, 1990)

(4)(b)        Agency Mortgage and Security Agreement dated as of November
              1, 1989 from Pyron Corporation and Niagara County
              Industrial Development Agency to The Bank of New York
              (Incorporated by reference from Exhibit (4)(b) of the
              Corporation's Annual Report on Form 10-K filed March 31,
              1990)

(4)(c)        Letter of Credit Reimbursement Agreement dated as of
              November 1, 1989 between Pyron Corporation and Chemical
              Bank (Incorporated by reference from Exhibit (4)(c) of the
              Corporation's Annual Report on Form 10-K filed March 31,
              1990)

(4)(d)        First Amendment to Letter of Credit Reimbursement Agreement
              dated as of November 1, 1989 between Pyron Corporation and
              Chemical Bank (Incorporated by reference from Exhibit
              (4)(d) of the Corporation's Annual Report on Form 10-K
              filed March 31, 1990)

(4)(e)        Second Amendment to Letter of Credit Reimbursement
              Agreement dated as of March 15, 1995 between Pyron
              Corporation and Chemical Bank (Incorporated by reference
              from Exhibit (4)(e) of the Corporation's Annual Report on
              Form 10-K filed March 30, 1995)

(4)(f)        Bank Mortgage and Security Agreement dated as of November
              1, 1989 from Pyron Corporation and Niagara County
              Industrial Development Agency to Chemical Bank
              (Incorporated by reference from Exhibit (4)(e) of the
              Corporation's Annual Report on Form 10-K filed March 31,
              1990)

(4)(g)        Building Loan Agreement dated as of November 1, 1989
              between Chemical Bank and Pyron Corporation (Incorporated
              by reference from Exhibit (4)(f) of the Corporation's
              Annual Report on Form 10-K filed March 31, 1990)



                                   12
<PAGE>   16

(4)(h)        Security Agreement dated as of November 1, 1989 between
              Pyron Corporation and Chemical Bank (Incorporated by
              reference from Exhibit (4)(g) of the Corporation's Annual
              Report on Form 10-K filed March 31, 1990)

(4)(i)        Corporate Guaranty dated as of November 1, 1989 from Zemex
              Corporation to Chemical Bank (Incorporated by reference
              from Exhibit (4)(h) of the Corporation's Annual Report on
              Form 10-K filed March 31, 1990)

(4)(j)        First Amendment to Corporate Guaranty dated as of November
              1, 1989 of Zemex Corporation to Chemical Bank (Incorporated
              by reference from Exhibit (4)(i) of the Corporation's
              Annual Report on Form 10-K filed March 31, 1990)

(4)(k)        Second Amendment to Corporate Guaranty dated as of March
              14, 1991 of Zemex Corporation to Chemical Bank
              (Incorporated by reference from Exhibit (4)(j) of the
              Corporation's Annual Report on Form 10-K filed March 31,
              1991)

(4)(l)        Third Amendment to Corporate Guaranty dated as of February
              25, 1992 of Zemex Corporation to Chemical Bank
              (Incorporated by reference from Exhibit (4)(m) of the
              Corporation's Annual Report on Form 10-K filed March 31,
              1993)

(4)(m)        Fourth Amendment to Corporate Guaranty dated as of March 8,
              1993 of Zemex Corporation to Chemical Bank (Incorporated by
              reference from Exhibit (4)(o) of the Corporation's Annual
              Report on Form 10-K filed March 31, 1993)

(4)(n)        Fifth Amendment to Corporate Guaranty dated as of March 15,
              1995 of Zemex Corporation to Chemical Bank (Incorporated by
              reference from Exhibit (4)(n) of the Corporation's Annual
              Report on Form 10-K filed March 30, 1995)

(4)(o)        Loan and Security Agreement dated as of March 15, 1995
              among Zemex Corporation and The Feldspar Corporation and
              NationsBank of Tennessee, N.A. and Chemical Bank and
              NationsBank of Tennessee, N.A., as Agent (Incorporated by
              reference from Exhibit (4)(p) of the Corporation's Annual
              Report on Form 10-K filed March 30, 1995)

(4)(p)        Amendment No. 1 dated as of March 12, 1997 to the Loan and
              Security Agreement dated as of March 15, 1995 among Zemex
              Corporation and The Feldspar Corporation and NationsBank of
              Tennessee, N.A. and Chemical Bank and NationsBank of
              Tennessee, N.A., as Agent

*(10)(a)      Key Executive Common Stock Purchase Plan (Incorporated by
              reference from Exhibit (10)(b) of the Corporation's Annual
              Report on Form 10-K filed March 31, 1991)

(10)(b)       Consent to Assignment of Lease and to Agreement Sublease,
              and permission to Make Payments dated November 7, 1978 each
              from Joberta Enterprises, Inc. to NL Industries, Inc. and
              The Feldspar Corporation (Incorporated by reference from
              Exhibit 10(pp) to the Corporation's Registration Statement
              on Form S-2, Registration No. 33-7774, filed on August 5,
              1986)

(10)(c)       Additional Lease Agreement dated as of November 1, 1989
              between Niagara County Industrial Development Agency and
              Pyron Corporation (Incorporated by reference from Exhibit
              (10)(ll) of the Corporation's Annual Report on Form 10-K
              filed March 31, 1990)


                                   13
<PAGE>   17

*(10)(d)      Subscription Agreement with Richard L. Lister dated
              November 26, 1991 (Incorporated by reference from Exhibit
              (5)(a) of the Corporation's Annual Report on Form 10-K
              filed March 31, 1992)

(10)(e)       1995 Stock Option Plan (Incorporated by reference from
              Exhibit B of the Corporation's 1995 Definitive Proxy
              Statement, filed on March 29, 1995)

(10)(f)       Suzorite Mica Product Inc.'s Mining Lease dated August 25,
              1975 between the Province of Quebec and Marietta Resources
              International Ltd. (Incorporated by reference from Exhibit
              10(av) of the Corporation's Annual Report on Form 10-K
              filed March 31, 1994)

(10)(g)       Employee Stock Purchase Plan (Incorporated by reference as
              Exhibit A to the Corporation's Proxy Statement filed May 6,
              1994)

(10)(h)       Asset Purchase Agreement dated December 7, 1994 between
              Whittaker, Clark & Daniels, Inc., Clark Minerals, Inc.,
              Cherokee Minerals, Inc. and Pioneer Talc Company and
              Suzorite Mineral Products, Inc. and Zemex Corporation
              (Incorporated by reference from Exhibit 10(u) of the
              Corporation's Annual Report on Form 10-K filed March 30,
              1995)

(10)(i)       1999 Stock Option Plan (Incorporated by reference from
              Exhibit A of the Corporation's 1999 Definitive Proxy
              Statement, filed on March 25, 1999)

(10)(j)       1999 Employee Stock Purchase Plan (Incorporated by
              reference as Exhibit B to the Corporation's Proxy Statement
              filed March 25, 1999)

(13)          1998 Annual Report to Shareholders

(21)          Subsidiaries of the Registrant

(23)(a)       Consent of Deloitte & Touche LLP, Independent Auditors

(27)          Financial Data Schedule




*   Management contract or compensatory plan or arrangement.



                                   14
<PAGE>   18


                       INDEPENDENT AUDITORS' REPORT



RE:      ZEMEX CORPORATION - ANNUAL REPORT ON FORM 10-K

We have examined the supporting schedule on page S-1 of this Annual
Report of Form 10-K for the year ended December 31, 1998. In our opinion,
this schedule presents fairly, when read in conjunction with the related
consolidated financial statements, the financial data required to be set
forth therein.



/s/ DELOITTE & TOUCHE LLP

Deloitte & Touche LLP
Chartered Accountants

Toronto, Canada
February 5, 1999




                                   15
<PAGE>   19


SIGNATURES


Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.

                                      ZEMEX CORPORATION



                                       By:/s/ RICHARD L. LISTER           
                                          --------------------------------------
Dated:  March 26, 1999                    Richard L. Lister
                                          President and Chief Executive Officer


Pursuant to the requirements of the Securities Exchange Act of 1934, this
report is signed below by the following persons on behalf of the
registrant and in the capacities and on the date indicated:

<TABLE>
<CAPTION>
SIGNATURE                                 TITLE                                       DATE

<S>                                       <C>                                    <C> 
/s/ PETER O. LAWSON-JOHNSTON              Chairman of the Board                   March 26, 1999
-----------------------------------       and Director
Peter O. Lawson-Johnston                  



/s/ RICHARD L. LISTER                     President and Chief Executive           March 26, 1999
-----------------------------------       Officer and Director
Richard L. Lister                         (Principal Executive Officer)


/s/ PAUL A. CARROLL                       Director                                March 26, 1999
-----------------------------------
Paul A. Carroll



/s/ MORTON A. COHEN                       Director                                March 26, 1999
-----------------------------------
Morton A. Cohen



/s/ JOHN M. DONOVAN                       Director                                March 26, 1999
-----------------------------------
John M. Donovan



/s/ R. PETER GILLIN                       Director                                March 26, 1999
-----------------------------------
R. Peter Gillin
</TABLE>


                                   16
<PAGE>   20

<TABLE>
<CAPTION>

SIGNATURE                                 TITLE                                       DATE



<S>                                       <C>                                    <C> 
/s/ GARTH A.C. MACRAE                     Director                                March 26, 1999
-----------------------------------
Garth A.C. MacRae



/s/ WILLIAM J. VANDEN HEUVEL              Director                                March 26, 1999
-----------------------------------
William J. vanden Heuvel



/s/ ALLEN J. PALMIERE                     Vice President, Chief Financial         March 26, 1999
-----------------------------------       Officer and Assistant Secretary
Allen J. Palmiere                         (Principal Financial and
                                          Accounting Officer)
</TABLE>

                                       17
<PAGE>   21





                             LIST OF EXHIBITS




EXHIBIT 13           1998 Annual Report to Shareholders

EXHIBIT 21           Subsidiaries of the Registrant

EXHIBIT 23(A)        Independent Auditors' Consent

EXHIBIT 27           Financial Data Schedule