<PAGE>   1

                       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, 1997

                          Commission file number 1-228

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


                 DELAWARE                                    13-5496920
   (State or other jurisdiction of                        (I.R.S. employer
    incorporation or organization)                      identification number)


           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
New York Stock Exchange                           Common Stock, $1.00 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 Stock,
$1.00 par value) held by non-affiliates as of March 23, 1998 (based on the
closing sale price of $9.3125 on the New York Stock Exchange) was $36,947,269.

As of March 23, 1998, 8,803,606 shares of the registrant's Common Stock, $1.00
par value, were outstanding.

                      DOCUMENTS INCORPORATED BY REFERENCE


  Annual Report to Shareholders for the Year Ended December 31, 1997  Part II

  Definitive Proxy Statement filed with the Commission
  pursuant to Regulation 14A with respect to the
  1998 Annual Meeting of Shareholders                                 Part III







<PAGE>   2




                                   FORM 10-K
                                 ANNUAL REPORT

                               TABLE OF CONTENTS
                                      AND
                             CROSS-REFERENCE SHEET


                                     PART I
<TABLE>
<CAPTION>
                                                                        PAGE
                                                                        ----
     <S>       <C>                                                      <C>
     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 (Unaudited)(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
</TABLE>

__________________________

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

(B)  Information responsive to this Item is set forth on page 26 of the
     registrant's Annual Report to Shareholders for the year ended December 31,
     1997 (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.






<PAGE>   3



(C)  Information responsive to this Item is set forth on page 51 of the Annual
     Report to Shareholders and is incorporated herein by reference.

(D)  Information responsive to this Item is set forth on pages 19 through 26
     of the Annual Report to Shareholders and is incorporated herein by
     reference.

(E)  Financial statements responsive to this Item are set forth on pages 27
     through 50 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 48 (Note
     15) and is incorporated herein by reference.






<PAGE>   4



                                     PART I

ITEM 1.  BUSINESS

GENERAL

Zemex Corporation (the "Corporation" or "Zemex"), a Delaware corporation, was
incorporated in 1985 as the successor to Pacific Tin Corporation.  Zemex is a
niche producer of industrial minerals and metal products.  Its principal
businesses are industrial minerals, metal powders, and aluminum waste
recycling.  Its major products include feldspar, feldspathic minerals, kaolin,
sand, mica, talc, ferrous and non ferrous powders, and aluminum dross
derivatives.

INDUSTRIAL MINERALS

The Corporation's industrial minerals segment consists of five wholly-owned
subsidiaries: The Feldspar Corporation ("TFC"), Suzorite Mica Products Inc.
("Suzorite") Suzorite Mineral Products, Inc. ("SMP"), Zemex Industrial
Minerals, Inc. and Zemex Mica Corporation.  The group is collectively referred
to as Zemex Industrial Minerals or "ZIM".

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 produced by dredging and wet separation at
the Edgar property.

TFC produces numerous products, including sodium and potassium feldspar,
silica, low iron sand, muscovite mica and kaolin clay, at its operating plants.
Feldspathic materials and kaolin are major raw materials 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, fiberglass, paints and plastics, and
television picture tubes. Industrial sand is used for filter, filler, beach,
blasting and concrete applications. TFC also produces a low iron sand product
for use in specialized glass applications.

Suzorite mines phlogopite mica in an open pit mining operation in Suzor
Township, Quebec, Canada, approximately 200 miles 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, Quebec, a suburb of Montreal.  Because of its distinct thermal
stability advantage over competitive materials, phlogopite mica is used in
technological and high temperature plastic applications; Suzorite's phlogopite
mica is used as a partial or complete substitute for asbestos in fire
retardation, 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 has talc operations in 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; these products are
directed primarily into the cosmetic and pharmaceutical industries.  The
production facility in Van Horn processes ores mined on-site for sale to the
coatings, plastics and ceramics industries.  The Benwood operation imports raw


                                       1




<PAGE>   5



materials, and processes a variety of calcium carbonate as well as a wide range
of talc products for ultimate use in the plastics industry.

In late 1996, SMP substantially completed the construction of a new mill at its
facility in 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, which will see application in
performance plastics, high end coatings and other markets, are currently being
tested and appraised by a select group of customers.  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 two muscovite plants in the Spruce
Pine, North Carolina area.  The new facilities, which are operating under the
name Zemex Mica Corporation, are located within close proximity of TFC's
feldspar plant where by-product muscovite mica is produced.  It is the
Corporation's intent to process TFC's excess mica by-product at the newly
acquired facilities.  Muscovite mica is marketed to the paint and plastics
industries, the same markets the Corporation currently services with its talc
and barytes products.

In February 1998, SMP entered into a joint venture with Industria Mineraria
Fabi S.r.l. ("Fabi"), a leading producer of talc in Europe.  Fabi paid $3.4
million to earn a 40% interest in the new joint venture company, Zemex
Fabi-Benwood, LLC, and SMP contributed its facility in Benwood, West Virginia.
This transaction provides SMP access to Fabi's talc processing technology and
premium ore reserves.

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

The Corporation's industrial minerals sales were $43.4 million in 1997,
compared with $40.5 million in 1996 and $37.1 million in 1995.  This business
segment reported operating income of  $5.2 million in 1997, $1.4 million in
1996 and $4.6 million in 1995.

During 1997, 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 $9.9 million in 1997 compared to $11.9 million in
1996 and $9.7 million in 1995.  Major capital spending in 1997 included the
completion of the sodium feldspar facility and the low iron sand plant at
Spruce Pine, North Carolina, and completion of a fine grind mill at SMP's plant
in Benwood, West Virginia.

METAL PRODUCTS

The metal products segment consists of Pyron Corporation and Pyron Metal
Powders, Inc. (together, "Pyron") and Alumitech, Inc., Aluminum Waste
Technology, Inc., ETS Schaefer Corporation, and AWT Properties, Inc.
(collectively, "Alumitech"), all of which are directly or indirectly
wholly-owned subsidiaries of Zemex.

Pyron operates plants located in Niagara Falls, New York; St. Marys,
Pennsylvania; and Greenback and Maryville, Tennessee.  The Maryville operation,
which was temporarily closed in order to optimize production efficiencies and
lower operating costs, was re-opened in late 1997 due to


                                       2


<PAGE>   6



increased demand.  In addition, a new water atomized copper powder process was
successfully commissioned at the Greenback location in late 1996.

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 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 than other
conventional metal working processes such as machining, casting and forging.

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 new blending plant, 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 designated 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 product line.

The Corporation acquired its initial interest in Alumitech in 1994 and
increased its ownership to 100% in 1995.  Alumitech has three processing
plants: an aluminum dross reprocessing plant in Cleveland, Ohio and two ceramic
fiber fabrication plants in Medina and Streetsboro, Ohio.  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 fiber-based heat containment systems located in Medina,
Ohio.  The Schaefer Brothers business was merged with Engineered Thermal
Systems to form ETS Schaefer Corporation.

Alumitech is an aluminum dross reprocessor that has developed and patented
proprietary technology to recycle secondary aluminum drosses into commercial
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 send any remaining materials 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 in the
production of calcium aluminate, refractory ceramic fiber and other
commercially acceptable products. Currently, competitive processes landfill
anywhere from 40%-75% of the volume of dross received, whereas Alumitech's
recycling process will 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
about thirteen years.

                                       3



<PAGE>   7



Alumitech also operates two ceramic fiber fabrication plants in Medina and
Streetsboro, Ohio.  At these facilities, refractory ceramic fiber components
are fabricated into products used in various high temperature applications.

Sales for the metal products group increased to $53.8 million in 1997 from
$46.0 million in 1996. Sales were $48.0 million in 1995.  The increase from
1996 to 1997 was due to higher volumes of ferrous and non ferrous metal powders
and higher aluminum prices.  During the same interval, operating income
increased from $1.9 million in 1996 to $3.2 million in 1997.  Operating income
was $3.7 million in 1995.   Management anticipates improved margins in this
segment in 1998 as a result of new products, higher metal powder production,
continuing cost reductions, and efficiency improvement programs.

Capital expenditures for the metal products group were $6.6 million in 1997 as
compared to $4.5 million in 1996 and $5.8 million in 1995.  The expenditures
were primarily directed to the construction and commercialization of a new NMP
processing facility at the Cleveland plant.  In 1998, capital expenditures are
anticipated to be $4.3 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.

SEASONALITY

The efficiency and productivity of the Corporation's operations can be affected
by unusually severe weather conditions.  During the winter of 1997, there were
minor production outages at the Corporation's operating facilities in North
Carolina and New York States due to inclement weather, but they were not
significant enough to materially affect 1997 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
powders industry is affected by imports of finished metal powder parts.
Product prices over the last several years have been strongly influenced by


                                       4
<PAGE>   8



costs of production and 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 operations, the major
factor affecting the supply of dross is the level of activity of the secondary
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 $1.0 million in 1997, $0.6
million in 1996 and $0.3 million in 1995.

Financial information about industry segments is set forth on pages 39 and 40
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 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, 1997
is set forth below:


<TABLE>
<CAPTION>
<S>                  <C>
Industrial Minerals  282
Metal Products       285
Corporate              7
                     ---
Total                574
                     ===
</TABLE>

Approximately 58 employees at the Corporation's metal powder operations in
Niagara Falls, New York, are covered by a collective bargaining agreement.
Negotiations are currently underway for a new agreement to replace the current
three-year agreement, which expires April 15, 1998.  At the ferrous metal powder
facilities in Tennessee, approximately 42 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, 1998
and one agreement expiring December 31, 1998.  On March 26, 1998, the hourly
employees at TFC's plant in Spruce Pine, North Carolina voted in favour of union
certification. Contract negotiations will commence shortly. The Corporation
considers its labor relations to be good.

                                       5
<PAGE>   9
three-year agreement, which expires April 15, 1998. At the ferrous metal powder
facilities in Tennessee, approximately 42 employees are covered by a four-year
agreement which expires February 28, 2002. Approximately 20 employees at
Suzorite are coverd 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, 1998 and one
agreement expiring December 31, 1998. The Corporation considers its labor
relations to be good.

FOREIGN OPERATIONS

The Corporation's international operations are located in Canada 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 and metal products operations sell their
products internationally to a wide variety of customers including the ceramics,
glass and powder metallurgy industries.  Export sales in these two segments
were less than 8% of total sales.


<TABLE>
<CAPTION>
  EXECUTIVE AND OTHER OFFICERS OF THE REGISTRANT
                                                                   SERVED IN
  OFFICER                  POSITION                        AGE   POSITION SINCE
  -------                  --------                        ---   --------------
  <S>                      <C>                             <C>   <C>
  Peter Lawson-Johnston    Chairman of the
                           Board of Directors              71         1975

  Richard L. Lister        President and
                           Chief Executive Officer         59         1993

  Allen J. Palmiere        Vice President,
                           Chief Financial Officer
                           and Assistant Secretary         45         1993

  Peter J. Goodwin         Vice President,
                           Zemex Corporation
                           President, Industrial Minerals  47         1994

  Terrance J. Hogan        President, Alumitech, Inc.      42         1995

  George E. Gillespie      President, Metal Powders        55         1997

  Patricia K. Moran        Corporate Secretary and
                           Assistant Treasurer             32         1995
</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.

                                       6
<PAGE>   10



Mr. Lister, who was elected to the board of directors on May 30, 1991, assumed
his duties as Vice Chairman of the Board of Directors on July 23, 1991 and as
President and Chief Executive Officer on June 1, 1993.  Mr. Lister was Vice
Chairman of Dundee Bancorp Inc. from October 1991 to May 1993.

Mr. Palmiere assumed the duties of Chief Financial Officer in October 1993.
From April 1992 to October 1993 he was a self-employed consultant.

Mr. Goodwin became a Vice President of the Corporation in August 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.

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 reserves for its Spruce Pine, North Carolina
facility.  The mineral deposits at the mines 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 reserves 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 products group has operations in Niagara Falls, New York; St. Marys,
Pennsylvania; Greenback, and Maryville, Tennessee; Cleveland, Ohio; and Medina
and Streetsboro, Ohio.  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.
The lease was established as part of the Industrial Development Revenue Bond
issued in November 1989 to finance the construction of an atomized steel






                                      -7-
<PAGE>   11



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, which was built in
1995, 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.  General office space comprises approximately 6,300 square
feet; there is approximately 87,000 square feet of production, storage and
shipping/receiving space.  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 60% of a 36,000 square foot
building, which it uses for its plant and office space.  The Medina facility is
leased and includes 19,000 square feet of plant and office space.

All facilities are maintained in good operating condition.


ITEM 3.  LEGAL PROCEEDINGS

On February 11, 1993, The Feldspar Corporation and other non-affiliated
companies were named as defendants in 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.  Dryvit alleges that between
approximately 1985 and 1990, sand purchased from TFC and other suppliers
utilized by Dryvit to manufacture exterior insulation finishes for the exterior
of buildings developed rust stains because the sand contained pyrite and
magnetic materials.  Dryvit seeks unspecified monetary damages and costs,
including the costs associated with the repair of the damaged structures.

TFC denies such allegations and claims, and the Corporation believes that it is
remote that this litigation will result in any material adverse effect to the
Corporation's financial condition or results of operations.  The Corporation
strongly believes that this action is without merit; however, no assurance can
be made as to the outcome of this litigation. Although the Corporation's
primary insurer has attempted to limit its coverage, the Corporation believes
that its primary and excess liability insurance is sufficient to cover any
potentially unfavorable outcome.


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

None.



                                      -8-

<PAGE>   12



                                    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 26 of registrant's
Annual Report to Shareholders for the year ended December 31, 1997 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 51 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 19 through 26 of the
Annual Report to Shareholders and is incorporated herein by reference.


ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Financial statements responsive to this Item are set forth on pages 27 through
50 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.



                                      -9-


<PAGE>   13



                                    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 1998 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 1998 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 1998 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 1998 Annual Meeting to be filed within 120 days after the end
of the fiscal year.

------------------
* Reference in this Annual Report on Form 10-K to material contained in the
Corporation's Proxy Statement for the 1998 Annual Meeting to be filed within
120 days after the fiscal year incorporate such material into this Report by
reference.





                                      -10-
<PAGE>   14



                                    PART IV


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

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

     (a)  Consolidated Balance Sheets at December 31, 1997 and 1996,
          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, 1997, which information is incorporated by
          reference under Item 8 of this report;

     (c)  Consolidated Statements of Income for the three years ended
          December 31, 1997, 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, 1997, 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;
          and

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

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


              SCHEDULE
              NUMBER            DESCRIPTION

                  -             Report of Independent Accountants

              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 1997
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 1997 Annual Report or notes related thereto.






                                      -11-
<PAGE>   15



3.  EXHIBITS

(3)(a) Certificate of Incorporation (Incorporated by reference from Exhibit 4(a)
       of the Corporation's Registration Statement on Form S-2, Registration No.
       33-7774, filed on August 5, 1986)

(3)(b) By-Laws (Incorporated by reference from Exhibit 3 of the Corporation's
       Quarterly Report on Form 10-Q filed on May 13, 1988)

(3)(c) Amended and Restated Certificate of Incorporation (Incorporated by
       reference from Exhibit A of the Corporation's Definitive Proxy Statement,
       filed on March 29, 1995)

(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)

(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)






                                      -12-
<PAGE>   16



(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)

*(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)  Ligonier Purchase Agreement and Second Plan of Reorganization dated
         March 2, 1992 among Pyron Metal Powders, Inc., a wholly-owned
         subsidiary of Zemex Corporation, Purchaser, and Ligonier Powders, Inc.,
         Seller (Incorporated by reference from Exhibit (5)(a) of the
         Corporation's Annual Report on Form 10-K filed March 31, 1993)


                                       13



<PAGE>   17



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

(10)(g)  Stock Purchase Agreement dated August 10, 1993 between Zemex
         Corporation, Zemex Canada Inc., an Ontario corporation and a direct
         wholly-owned subsidiary of Zemex Corporation, Dundee Bancorp Inc., an
         Ontario corporation, and Dundee Bancorp International Inc., a Delaware
         corporation, and a direct wholly-owned subsidiary of Dundee Bancorp
         Inc., with respect to the acquisition of Suzorite Mica Products Inc.
         (Incorporated by reference from Exhibit 2 of the Corporation's Current
         Report on Form 8-K filed September 7, 1993)

(10)(h)  Capital Stock Purchase Warrant dated September 14, 1993 issued to
         Dundee Bancorp International Inc. pursuant to the Stock Purchase
         Agreement referred to in 10(m).  (Incorporated by reference from
         Exhibit 4(a) of the Corporation's Current Report on Form 8-K filed
         September 7, 1993)

(10)(i)  Registration Rights Agreement dated September 14, 1993 between Zemex
         Corporation and Dundee Bancorp International Inc.  (Incorporated by
         reference from Exhibit 4(b) of the Corporation's Current Report on Form
         8-K filed September 7, 1993)

(10)(j)  Asset Purchase Agreement dated September 3, 1993 between U.S. Silica
         Company, The Feldspar Corporation and Zemex Corporation with respect to
         the sale of the Virginia aplite facility (Incorporated by reference
         from Exhibit 10(at) of the Corporation's Annual Report on Form 10-K
         filed March 31, 1994)

(10)(k)  Stock Purchase Agreement dated November 15, 1993 between Americo Malay
         Mineral Company and Zemex Corporation with respect to the sale of
         2,500,002 common shares of Perangsang Pasifik Senderian Berhad, a
         corporation organized and existing under the laws of the Federal
         Republic of Malaysia (Incorporated by reference from Exhibit 10(au) of
         the Corporation's Annual Report on Form 10-K filed March 31, 1994)

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

(10)(n)  Stockholders Agreement dated June 10, 1994 among Alumitech, Inc.,
         Clarion Capital Corporation, DCC Equities Limited and Moshe Dan
         Yerushalmi, John Hocevar and Terrance Hogan and Zemex Corporation
         (Incorporated by reference as Exhibit 10(ax) to the Corporation's
         Registration Statement on Form S-1, Registration No. 33-82638, filed on
         August 22, 1994)

(10)(o)  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)

(13)     1997 Annual Report to Shareholders


                                       14



<PAGE>   18



(22)    Subsidiaries of the Registrant

(24)(a) Consent of Deloitte & Touche

(27)     Financial Data Schedule

The Corporation will furnish copies of these documents to requesting
shareholders upon payment of $10.80 per document.





*    Management contract or compensatory plan or arrangement.


                                       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  23, 1998           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 LAWSON-JOHNSTON       Chairman of the Board            March 23, 1998
-----------------------------   and Director
Peter Lawson-Johnston



/s/ RICHARD L. LISTER           President and                    March 23, 1998
-----------------------------   Chief Executive
Richard L. Lister               Officer and Director
                                (Principal Executive Officer)


/s/ PAUL A. CARROLL             Director                         March 23, 1998
-----------------------------
Paul A. Carroll



/s/ MORTON A. COHEN             Director                         March 23, 1998
-----------------------------
Morton A. Cohen



/s/ JOHN M. DONOVAN             Director                         March 23, 1998
-----------------------------
John M. Donovan



/s/ THOMAS B. EVANS, JR.        Director                         March 23, 1998
-----------------------------
Thomas B. Evans, Jr.
</TABLE>


                                       16



<PAGE>   20

<TABLE>
<CAPTION>
SIGNATURE                                      TITLE                           DATE
---------                                      -----                           ----

<S>                                           <C>                          <C>
/s/ NED GOODMAN                               Director                     March 23, 1998
----------------------------------------
Ned Goodman



/s/ PATRICK H. O'NEILL                        Director                     March 23, 1998
----------------------------------------
Patrick H. O'Neill



/s/ WILLIAM J. VANDEN HEUVEL                  Director                     March 23, 1998
----------------------------------------
William J. vanden Heuvel



/s/ ALLEN J. PALMIERE                        Vice President,               March 23, 1998
----------------------------------------     Chief Financial
Allen Palmiere                               Officer and
                                             Assistant Secretary
                                             (Principal Financial and
                                             Accounting Officer)
</TABLE>


                                       17




<PAGE>   21



                                LIST OF EXHIBITS





<TABLE>
<CAPTION>
               <S>            <C>
               EXHIBIT 13     1997 Annual Report to Shareholders

               EXHIBIT 22     Subsidiaries of the Registrant

               EXHIBIT 24(A)  Report of Independent Accountants

               EXHIBIT 27     Financial Data Schedule
</TABLE>