Surfactant mixtures as collectors for the flotation of non-sulfidic ores

Mixtures of PA1 (a) at least one alkyl or alkenyl polyethylene glycol ether which is terminally blocked by a hydrophobic radical, and PA1 (b) at least one anion-active surfactant are used as collectors in the flotation of non-sulfide ores.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the use of terminally blocked alkyl 
polyethyleneglycol ethers as co-collectors in the flotation of 
non-sulfidic ores together with anion-active surfactant components, and to 
a process for the separation of non-sulfidic ores by flotation. 
2. Statement of Related Art 
Flotation is a separation technique commonly used in the dressing of 
mineral ores for separating valuable minerals from the gangue. 
Non-sulfidic minerals in the context of the present invention are, for 
example, apatite, fluorite, scheelite, baryta, iron oxides and other metal 
oxides, for example the oxides of titanium and zirconium, and also certain 
silicates and aluminosilicates. In dressing processes based on flotation, 
the ore is normally first subjected to preliminary size-reduction, 
dry-ground, but preferably wet-ground, and suspended in water. Collectors 
or collector mixtures are then normally added, often in conjunction with 
frothers and, optionally, other auxiliary reagents such as regulators, 
depressors (deactivators) and/or activators, in order to facilitate 
separation of the valuable minerals from the unwanted gangue constituents 
of the ore in the subsequent flotation process. These reagents are 
normally allowed to act on the finely ground ore for a certain time 
(conditioning) before air is blown into the suspension (flotation) to 
produce a froth at its surface. The collector acts as a hydrophobicizing 
agent on the surface of the minerals causing the minerals to adhere to the 
gas bubbles formed during the aeration step. The mineral constituents are 
selectively hydrophobicized so that the unwanted consituents of the ore do 
not adhere to the gas bubbles. The mineral-containing froth is stripped 
off and further processed. The object of flotation is to recover the 
valuable material of the ores in as high a yield as possible while at the 
same time obtaining a high enrichment level of the valuable mineral. 
Surfactants and, in particular, anionic and cationic surfactants are used 
in the flotation-based dressing of ores. Known anionic collectors are, for 
example, saturated or unsaturated fatty acids, alkyl sulfates, alkylether 
sulfates, alkyl sulfosuccinates, alkyl sulfosuccinamides, alkyl benzene 
sulfonates, alkyl sulfonates, petroleum sulfonates, acyl lactylates, alkyl 
phosphates, and alkyl ether phosphates. 
In contrast to anionic and cationic surfactants, nonionic surfactants are 
hardly ever used as collectors in flotation. In Trans. Inst. Met. Min. 
Sect. C 84 (1975), pages 34 to 39, A. Doren, D. Vargas and J. Goldfarb 
report on flotation tests on quartz, cassiterite and chrysocolla which 
were carried out with an adduct of 9 to 10 moles ethylene oxide with 
octylphenol as collector. Combinations of ionic and nonionic surfactants 
are also occasionally described as collectors in the relevant literature. 
Thus, A. Doren, A. van Lierde and J. A. de Cuyper report in Dev. Min. 
Proc. 2 (1979), pp. 86-109 on flotation tests carried out on a 
non-sulfidic tin ore with a combination of an adduct of 9 to 10 moles 
ethylene oxide with octylphenol and an octadecyl sulfosuccinate. In A. M. 
Gaudin Memorial Volume, edited by M. C. Fuerstenau, AIME, New York, 1976, 
Vol. 1, pp. 597-620, V. M. Lovell describes flotation tests carried out on 
an apatite with a combination of tall oil fatty acid and nonylphenol 
tetraglycol ether. 
Published German patent application No. 35 17 154.5 (U.S. pending 
application Ser. No. 861,672, filed May 11, 1985) proposes the use of 
nonionic ethylene oxide/propylene oxide adducts in addition to anionic, 
cationic or ampholytic surfactants as aids in the flotation of 
non-sulfidic ores. 
In many instances, the anionic and ampholytic collectors used for flotation 
do not lead to satisfactory recovery of the valuable minerals when used in 
economically reasonable quantities. 
DESCRIPTION OF THE INVENTION 
Other than in the operating examples, or where otherwise indicated, all 
numbers expressing quantities of ingredients or reaction conditions used 
herein are to be understood as modified in all instances by the term 
"about". 
An object of the present invention is to find improved collectors which 
make flotation processes more economical, i.e. with which it is possible 
to obtain either greater yields of valuable minerals for the same 
quantities of collector and for the same selectivity, or at least the same 
yields of valuable materials for reduced quantities of collector. 
It has been found that certain terminally blocked alkyl or alkenyl 
polyethylene glycol ethers represent highly effective additions as 
co-collectors to anion-active surfactants of the type known as collectors 
for the flotation of non-sulfidic ores. 
The present invention relates to the use of mixtures of 
(a) at least one alkyl or alkenyl polyethylene glycol ether which is 
terminally blocked by a hydrophobic radical, and 
(b) at leaast one anion-active surfactant as collectors in the flotation of 
nonsulfidic ores. 
Alkyl polyethylene glycol ethers of formula 1 
EQU R.sup.1 --O--(CH.sub.2 CH.sub.2 O).sub.n --R.sup.2 ( 1) 
wherein R.sup.1 represents a straight-chain or branched alkyl or alkenyl 
radical having 8 to 22 carbon atoms, R.sup.2 represents a straight-chain 
or branched alkyl radical having 1 to 8 carbon atoms or a benzyl radical 
and n represents a number from 1 to 30 are contemplated in particular as 
component (a). 
The terminally blocked alkyl polyethylene glycol ethers set forth above 
constitute a class of compounds which is known from the literature; they 
may be obtained in accordance with known methods of organic synthesis 
(see, for example, U.S. Pat. No. 2,856,434, U.S. Pat. Nos. 3,281,475, 
4,366,326, European patent application No. 0,030,397 and U.S. Pat. No. 
4,548,729). These terminally blocked alkyl or alkenyl polyethylene glycol 
ethers are chemically more resistant than the corresponding alkyl or 
alkenyl polyethylene glycol ethers containing a free terminal hydroxyl 
group. Since terminally blocked alkyl or alkenyl polyethylene glycol 
ethers foam less than their precursors in aqueous solution, they also are 
useful for (alkaline) cleaning processes involving heavy mechanical 
stressing. 
Known fatty alcohols may be used as starting materials for the terminally 
blocked alkyl or alkenyl polyethylene glycol ethers. The fatty alcohol 
component may consist of straight-chain and branched, saturated and 
unsaturated compounds of this category containing from 8 to 22 carbon 
atoms, for example, n-octanol, n-decanol, n-dodecanol, n-tetradecanol, 
n-hexadecanol, n-octadecanol, n-eicosanol, n-docosanol, n-hexadecenol, 
isotridecanol, isooctadecanol and n-octadecanol. The above fatty alcohols 
may individually form the basis of the terminally blocked alkyl and 
alkenyl polyethylene glycol ethers. However, products based on fatty 
alcohol mixtures are generally used, the fatty alcohol mixtures emanating 
from the fatty acid component of fats and oils of animal or vegetable 
origin. Fatty alcohol mixtures such as these may be obtained in known 
manner from the naturally occurring fats and oils, inter alia, by 
transesterification of the triglycerides with methanol and subsequent 
catalytic hydrogenation of the fatty acid methyl ester. In this case, both 
the fatty alcohol mixtures accumulating during production and also 
suitable fractions having a limited chain length spectrum may be used as 
basis for the production of the terminally blocked alkyl or alkenyl 
polyethylene glycol ethers. In addition to the fatty alcohol mixtures 
obtained from natural fats and oils, it is also possible to use synthetic 
fatty alcohol mixtures, for example the known Ziegler and oxo fatty 
alchols, as starting materials for the production process. 
Terminally blocked alkyl polyethylene glycol ethers based on fatty alcohols 
having 12 to 18 carbon atoms, that is, compounds of formula 1 wherein 
R.sup.1 represents an alkyl or alkenyl radical having 12 to 18 carbon 
atoms are preferred components (a) in the surfactant mixtures to be used 
in accordance with the invention. 
To produce the terminally blocked alkyl and alkenyl polyethylene glycol 
ethers, the fatty alcohols described above are preferably first reacted 
with 1 to 30 moles, preferably 2 to 15 moles of ethylene oxide per mole of 
fatty alcohol. The reaction with ethylene oxide is carried out under the 
known alkoxylation conditions, preferably in the presence of suitable 
alkaline catalysts. 
The etherification of the free hydroxyl groups, necessary for the terminal 
blocking of the alkyl or alkenyl polyethylene glycol ethers, can be 
carried out in accordance with methods known from the literature (see, for 
example, U.S. Pat. No. 2,856,434, U.S. Pat. No. 3,281,475, and U.S. Pat. 
No. 4,366,326, European patent application 0,030,397 and U.S. Pat. No. 
4,548,729). The etherification of the free hydroxyl groups is preferably 
carried out under the known conditions of Williamson's ether synthesis 
using linear or branched C.sub.1 -C.sub.8 -alkyl halides, for example 
n-propyl iodide, n-butyl chloride, sec.-butyl bromide, tert.-butyl 
chloride, n-amyl chloride, ter.-amyl bromide, n-hexyl chloride, n-heptyl 
bromide, n-octyl chloride, and benzyl chloride. In this connection, it may 
be expedient to use the alkyl halide and alkali, such as an alkali metal 
hydroxide, in a stoichiometric excess, for example of from 100% to 200%, 
over the hydroxyl groups to be etherified. A suitable method is disclosed 
in U.S. Pat. No. 4,548,729. In a preferred embodiment of the invention, 
alkyl polyethylene glycol ethers which are terminally blocked by n-butyl 
radicals are used as component (a) in the surfactant mixtures of the 
invention. 
The anion-active surfactants contemplated as component (b) in the 
surfactant mixtures to be used in accordance with the invention are of the 
type known per se as collectors for the flotation of non-sulfidic ores. 
They are, in particular, anion-active surfactants selected from fatty 
acids, alkyl sulfates, alkyl ether sulfates, alkyl sulfosuccinates, alkyl 
sulfosuccinamides, alkyl benzene sulfonates, alkyl sulfonates, petroleum 
sulfonates, acyl lactylates, alkyl phosphates and alkyl ether phosphates. 
Suitable fatty acids include the straight-chain fatty acids containing from 
12 to 18 carbon atoms and more especially from 16 to 18 carbon atoms 
obtained from vegetable or animal fats and oils, for example by lipolysis 
and, optionally, fractionation and/or separation by the hydrophilization 
process. Oleic acid and tall oil fatty acid are preferred. 
Suitable alkyl sulfates include the water-soluble salts of sulfuric acid 
semiesters of fatty alcohols having 8 to 22 carbon atoms and preferably of 
fatty alcohols having 12 to 18 carbon atoms which may be linear or 
branched. The foregoing discussions of the fatty alcohol component of the 
alkyl or alkenyl polyethylene glycol ethers to be used as component (a) 
also apply to the fatty alcohol component of the sulfuric acid semiesters. 
The water-soluble salts are preferably the alkali metal salts, more 
preferably the sodium salts. 
Suitable alkyl ether sulfates include the water-soluble salts of sulfuric 
acid semiesters of reaction products of 1 to 30 moles of ethylene oxide, 
preferably 2 to 15 mole ethylene oxide and fatty alcohols having 8 to 22 
carbon atoms, preferably 12 to 18 carbon atoms. The foregoing discussions 
of the fatty alcohol component of the alkyl or alkenyl polyethylene glycol 
ethers to be used as component (a) also apply to the fatty alcohol 
component of these sulfuric acid semiesters. The water-soluble salts are 
preferably the alkali metal salts or ammonium salts, more preferably the 
sodium and ammonium salts. 
Suitable alkyl sulfosuccinates include the water-soluble salts of 
sulfosuccinic acid semiesters of fatty alcohols having 8 to 22 carbon 
atoms and preferably of fatty alcohols having 12 to 18 carbon atoms. These 
alkyl sulfosuccinates may be obtained, for example, by reaction of 
corresponding fatty alcohols or fatty alcohol mixtures with maleic acid 
anhydride and subsequent addition of alkali metal sulfite or alkali metal 
hydrogen sulfite. The foregoing discussions of the fatty alcohol component 
of the alkyl or alkenyl polyethylene glycol ethers to be used as component 
(a) also apply to the fatty alcohol component of the sulfosuccinic acid 
esters. The water-soluble salts are preferably the alkali metal salts, 
more preferably the sodium salts. 
The alkyl sulfosuccinamides which can be employed as component (b) 
correspond to the following formula 
##STR1## 
in which R is an alkyl or alkenyl group containing from 8 to 22 carbon 
atoms and preferably from 12 to 18 carbon atoms, R' represents hydrogen or 
a C.sub.1 -C.sub.3 alkyl group and M is a hydrogen ion, an alkali metal 
cation, for example sodium, potassium, lithium etc., or an ammonium ion, 
preferably a sodium or ammonium ion. The alkyl sulfosuccinamides 
corresponding to formula II are known substances obtained, for example, by 
reaction of corresponding primary or secondary amines with maleic acid 
anhydride and subsequent addition of alkali metal sulfite or alkali metal 
hydrogen sulfite. Examples of primary amines suitable for use in the 
preparation of the alkyl sulfosuccinamides are n-octyl amine, n-decyl 
amine, n-dodecyl amine, n-tetradecyl amine, n-hexadecyl amine, n-octadexyl 
amine, n-eicosyl amine, n-docosyl amine, n-hexadecenyl amine and 
n-octadecenyl amine. The above amines can individually form the basis of 
the alkyl sulfosuccinamides. However, amine mixtures of which the alkyl 
groups are derived from the fatty acid component of fats and oils of 
animal or vegetable origin are normally used for preparing the alkyl 
sulfosuccinamides. It is known that amine mixtures such as these can be 
obtained from the fatty acids of naturally occurring fats and oils 
obtained by lipolysis via the corresponding nitriles by reduction with 
sodium and alcohols or by catalytic hydrogenation. Secondary amines 
suitable for use in the preparation of the alkyl sulfosuccinamides 
corresponding to formula II include the N-methyl and N-ethyl derivatives 
of the primary amines disclosed above. 
Alkyl benzene sulfonates suitable for use as component (b) correspond to 
the following formula 
EQU R--C.sub.6 H.sub.4 --SO.sub.3 M (III) 
in which R is a straight-chain or branched alkyl group containing from 4 to 
16 and preferably from 8 to 12 carbon atoms and M is an alkali metal 
cation, e.g. sodium, potassium, lithium etc., or ammonium ion, preferably 
a sodium ion. 
Alkyl sulfonates suitable for use as component (b) correspond to the 
following formula 
EQU R--SO.sub.3 M (IV) 
in which R is a straight-chain or branched alkyl group preferably 
containing 8 to 22 carbon atoms, and more preferably, from 12 to 18 carbon 
atoms, and M is an alkali metal cation, e.g. sodium, potassium, lithium 
etc., or an ammonium ion, preferably a sodium ion. 
The petroleum sulfonates suitable for use as component (b) are obtained 
from lubricating oil fractions, generally by sulfonation with sulfur 
trioxide or oleum and subsequent neutralization. Those compounds in which 
most of the hydrocarbon radicals contain from 8 to 22 carbon atoms are 
particularly suitable. 
The alkyl lactylates suitable for use as component (b) correspond to the 
following formula 
##STR2## 
in which R is an aliphatic, cycloaliphatic or alicyclic radical containing 
from 7 to 23 carbon atoms and X is a salt-forming cation, e.g. an alkali 
metal cation or an ammonium ion, R is preferably an aliphatic, linear or 
branched chain hydrocarbon radical which may be saturated, and optionally 
substituted by one or more hydroxyl groups. The use of the acyl lactylates 
corresponding to formula V as collectors in the flotation of nonsulfidic 
ores is described in U.S. Pat. No. 4,457,850. 
Alkyl phosphates and alkyl ether phosphates that can be employed herein 
correspond to the following formulas: 
##STR3## 
in which R represents an alkyl or alkenyl residue having from 8 to 22 
carbon atoms and M represents hydrogen, an alkali metal, or ammonium, 
preferably sodium or ammonium. The subscripts m, n and q in the case of 
the alkyl phosphates are equal to zero; in the case of the alkyl ether 
phosphates each represents a number of from 2 to 15. The compounds of 
formulas VI and VII are known substances, which can be synthesized 
according to known methods. Suitable starting materials for the production 
of the alkyl phosphates include C.sub.8 -C.sub.22 straight chain or 
branched alcohols having about 8 to 22 carbon atoms described above in 
connection with the alkyl sulfates and sulfuric acid half esters. Alkyl 
phosphates in which R has about 10 to 16 carbon atoms are preferably 
preferred. Starting materials for the production of the alkyl ether 
phosphates include addition products of 2 to 15 moles ethylene oxide with 
the above described alcohols containing 8 to 22 carbon atoms. These 
addition products can be synthesized according to known methods. In the 
case of the alkyl ether phosphates, compounds of formulas VI and VII, in 
which R contains about 18 to 22 carbon atoms, are preferred. 
In the mixtures of terminally blocked alkyl polyethylene glycol ethers and 
anion-active surfactant to be used in accordance with the invention, the 
weight ratio of the components (a):(b) is in the range of from 1:20 to 3:1 
and preferably in the range of from 1:10 to 1:1. 
In practice, the collector mixtures used in accordance with the invention 
replace the known collectors in known flotation processes for non-sulfidic 
ores. Accordingly, other reagents commonly used, such as frothers, 
regulators, activators, deactivators, etc., are also advantageously added 
to the aqueous suspensions of the ground ores in addition to the collector 
mixtures. Flotation is carried out under the same conditions as 
state-of-the-art processes. In this connection, reference is made to the 
following literature references on technological background of ore 
preparation: A. Schubert, Aufbereitung fester mineralischer Rohstoffe, 
Leipzig 1967; B. Wills, Mineral Processing Technology, New York, 1978; D. 
B. Purchas (ed.) Solid/Liquid Separation Equipment Scale-Up, Croydon 1977; 
E. S. Perry, C. J. van Oss, E. Grushka (ed.), Separation and Purification 
Methods, New York, 1973-1978. 
The present invention also relates to a process for the separation of 
non-sulfidic ores by flotation, in which crushed ore is mixed with water 
to form a suspension, air is introduced into the suspension in the 
presence of the collector system of the invention and the froth formed is 
stripped off together with the mineral therein. To obtain economically 
useful results for the flotation process, the collector mixtures of the 
invention are used in quantities of from 50 to 2000 g per metric ton of 
crude ore, preferably in quantities of from 100 to 1500 g per metric ton 
of crude ore, in the flotation of nonsulfidic ores. 
The collector mixtures of the invention are used with particular advantage 
in the dressing of ores such as scheelite, baryta, apatite, or iron ores. 
The following Examples, given for illustration purposes only, demonstrate 
the superiority of the mixtures of terminally blocked alkyl or alkenyl 
polyethyleneglycol ethers and anion active surfactants used in accordance 
with the invention over collectors known from the prior art. 
The tests were carried out under laboratory conditions in some cases with 
increased collector concentrations considerably higher than necessary in 
practice. Accordingly, the potential applications and in-use conditions 
are not limited to the separation, objectives and test conditions 
described in the Examples. All percentages are percentages by weight, 
unless otherwise indicated. The quantities indicated for reagents are all 
based on active substance.

EXAMPLES 
Example 1 
The material to be floated was a scheelite ore from Austria which had the 
following chemical composition with respect to its principal constituents: 
______________________________________ 
WO.sub.3 
0.3% 
CaO 8.8% 
SiO.sub.2 
55.8% 
______________________________________ 
The ore had the following particle size distribution: 
______________________________________ 
28% &lt;25 .mu.m 
43% 25-100 .mu.m 
29% 100-200 .mu.m 
______________________________________ 
The collector mixture used contained the sodium salt of an N-C.sub.12-8 
-alkylsulfosuccinamide as the anion-active component (b). A fatty alcohol 
polyethylene glycol n-butylether based on an adduct of 7 moles ethylene 
oxide with one mole of a fatty alcohol mixture having a chain length of 
from 12 to 18 carbon atoms was used as the nonionic component (a) 
according to the invention. The weight ratio of component (b) to component 
(a) was 2:1. 
The flotation tests were carried out in a 1 liter flotation cell using a 
Humbold-Wedag laboratory flotation machine of the type manufactured by KHD 
Industrieanlagen AG, Humbold-Wedag, Cologne (see Seifen-Fette-Wachse 105 
(1979), page 248). Deionized water was used to prepare the pulp. The pulp 
density was 400 g/l. Waterglass was used as depressor in a quantity of 
2000 g per metric ton. The conditioning time of the depressor was 10 
minutes at a stirring speed of 2000 rpm. Flotation was carried out at the 
pH value of approx. 9.5 obtained by addition of the waterglass. The 
collector dosage is shown in Table 1 below. The conditioning time of the 
collector was 3 minutes. The results obtained are shown in Table 1. 
Comparison Example 1 
A flotation test was carried out in accordance with Example 1 using the 
alkyl sulfosuccinamide of Example 1 alone as collector. The results 
obtained are shown in Table 1. 
Comparison Example 2 
A flotation test was carried out in accordance with Example 1 using a 
collector mixture of the alkyl sulfosuccinamide of Example 1 and an adduct 
of 2 moles ethylene oxide and 4 moles propylene oxide with 1 mole of a 
fatty alcohol having a chain length of from 12 to 18 carbon atoms in a 
weight ratio of 2:1. 
The flotation results are shown in Table 1. 
TABLE 1 
______________________________________ 
Flotation of scheelite 
Total Recovery 
dosage Total WO.sub.3 
Concentrate content (%) 
Example (g/t) (%) (%) WO.sub.3 
CaO SiO.sub.2 
______________________________________ 
Comparison 
500 0.6 19 10.6 8.6 34.8 
Example 1 
Comparison 
300 2.5 65 8.7 26.6 22.3 
Example 2 
100 0.8 5 2.4 16.3 35.8 
.SIGMA.400.sup. 
3.2 70 7.2 24.2 25.5 
Example 1 
300 2.2 88 13.3 32.9 26.9 
100 1.2 6 1.5 16.8 38.4 
.SIGMA.400.sup. 
3.4 94 9.1 27.1 31.0 
______________________________________ 
As can be seen from Table 1, the recovery of WO.sub.3 may be considerably 
increased by the combination of the anion-active surfactant with the 
terminally blocked polyethylene glycol ether of Example 1 with a 40% lower 
collector dosage, selectivity also being more favorable. The collector 
mixture according to the invention also has distinct advantages with 
respect to selectivity and recovery over the mixture of alkyl 
sulfosuccinamide and fatty alcohol alkoxylate of Comparison Example 2. 
Example 2 
The flotation batch used was the same as in Example 1. The collector used 
contained the alkyl sulfosuccinamide of Example 1 as the anion-active 
component and an n-butylether based on an adduct of 5 moles ethylene oxide 
with 1 mole of a fatty alcohol mixture having a chain length of from 12 to 
18 carbon atoms in a weight ratio of 2:1. 
The flotation tests were carried out at room temperature in a modified 
Hallimond tube (microflotation cell) according to B. Dobias, Colloid & 
Polymer Science, 259 (1981), pages 115 to 116. Each test was carried out 
with 2 g of ore. Distilled water was used to prepare the pulp. The 
conditioning time was 15 minutes in each test. During flotation, an air 
stream was passed through the pulp at a rate of 4 ml/minute. In every 
test, the flotation time was 2 minutes. 
The results obtained are shown in Table 2. 
Example 3 
The flotation batch used was the same as in Example 1. The collector 
mixture used contained the alkyl sulfosuccinamide of Example 1 as the 
anion-active component and an alkyl polyethylene glycol n-butyl-ether 
based on an adduct of 10 moles ethylene oxide with 1 mole of a fatty 
alcohol mixture having a chain length of from 12 to 18 in a weight ratio 
of 2:1. The flotation was carried out under the same conditions as in 
Example 2. 
The flotation results are shown in Table 2. 
Comparison Example 3 
The flotation batch was the same as in Example 1. The collector mixture 
contained the alkyl sulfosuccinamide of Example 1 as the anion-active 
component and an adduct of 2 moles ethylene oxide and 4 moles propylene 
oxide with 1 mole of a fatty alcohol mixture having a chain length of from 
12 to 18 carbon atoms in a weight ratio of 2:1. The flotation was carried 
out under the same conditions as in Example 2. 
The results of the flotation test are shown in Table 2. 
TABLE 2 
______________________________________ 
Flotation of scheelite 
Total Recovery 
dosage WO.sub.3 
Concentrate content (%) 
Example (g/t) Total (%) WO.sub.3 
CaO SiO.sub.2 
______________________________________ 
Comparison 
500 6.6 57 2.8 15.7 44.9 
Example 3 
Example 2 
500 7.7 71 3.0 15.1 42.5 
Example 3 
300 5.5 53 3.2 13.6 47.0 
______________________________________ 
The test results in Table 2 show that mixtures with fatty alcohol 
polyethylene glycol n-butylethers of different degrees of ethoxylation are 
superior with respect to flotation results compared to a corresponding 
collector mixture with a non-terminally blocked fatty alcohol 
polyalkoxylate as the nonionic component. 
Example 4 
The flotation batch used consisted of the tailings from an iron ore 
dressing plant which had the following chemical composition with respect 
to the principal constituents: 
11.6% P.sub.2 O.sub.5 
34.9% SiO.sub.2 
13.0% Fe.sub.2 O.sub.3 
18.9% MgO 
The flotation batch had the following particle size distribution: 
______________________________________ 
&lt;25 .mu.m 
5.7% 
25-100 .mu.m 
15.0% 
200-500 .mu.m 
69.8% 
500-1000 .mu.m 
8.7% 
&gt;1000 .mu.m 
0.8% 
______________________________________ 
The Na/NH.sub.4 salt of a monoalkyl sulfosuccinate whose alkyl radical was 
derived from a technical oleyl/cetyl alcohol was used as the anion-active 
collector component. An alkyl polyethylene glycol n-butylether based on an 
adduct of 7 moles ethylene oxide with 1 mole of a fatty alcohol mixture 
having a chain length of from 12 to 18 carbon atoms was used as the 
nonionic surfactant. The ratio of the Na/NH.sub.4 salt to the terminally 
blocked alkyl polyethylene glycol n-butylether was 65% to 35%. 
The flotation tests were carried out at room temperature in a 1-liter 
laboratory flotation cell (Denver Equipment model D-1). Tapwater having a 
hardness of 16.degree. Gh was used to prepare the pulp. 
The pulp density was 500 g/l; the pH value was adjusted to 9.5 with sodium 
hydroxide before addition of the collector. After rougher flotation (for 6 
minutes), the concentrate was purified twice. Flotation was carried out at 
1200 l/minute in every stage. The flotation results are shown in Table 3 
below. 
Comparison Example 4 
The flotation batch used was the same as in Example 4. The collector used 
was the Na/NH.sub.4 salt of the monoalkyl sulfosuccinate of Example 4. The 
flotation was carried out under the same conditions as in Example 4. The 
results are shown in Table 3 below. 
Comparison Example 5 
The flotation batch used was the same as in Example 4. The collector 
mixture used contained the Na/NH.sub.4 salt of the monoalkyl 
sulfosuccinate of Example 4 and an adduct of 2 moles ethylene oxide and 4 
moles of propylene oxide with 1 mole of a fatty alcohol mixture having a 
chain length of from 12 to 18 carbon atoms. The collector mixture 
consisted of 65% of the anion-active surfactant and 35% of the fatty 
alcohol ethoxylate. The flotation was carried out under the same 
conditions as in Example 4. The results are shown in Table 3 below. 
TABLE 3 
__________________________________________________________________________ 
Flotation of apatite 
Flotation 
Total re- 
Valuable mineral 
Content (%) 
g/t 
Example stage 
covery (%) 
recovery (%) 
P.sub.2 O.sub.5 
__________________________________________________________________________ 
280 
Comparison Example 4 
rt 72.6 10 1.7 
ct 5.0 11 26.3 
conc. 
22.4 79 42.3 
batch 
100.0 100 12.0 
200 
Example 4 rt 64.3 2 0.1 
ct 6.5 2 6.1 
conc. 
29.2 96 40.0 
batch 
100.0 100 12.1 
200 
Comparison Example 5 
rt 76.3 27 4.2 
ct 5.2 7 15.7 
conc. 
18.5 66 41.7 
batch 
100.0 100 11.7 
__________________________________________________________________________ 
rt = tailings of rougher flotation 
ct = tailings of purifying flotation (total) 
conc. = concentrate 
The flotation tests summarized in Table 3 clearly show that the collector 
combination according to Example 4 enables the collector dosage to be 
reduced by about 30% for an increased recovery of valuable material. A 
corresponding collector mixture according to Comparison Example 5 gives a 
much lower recovery of apatite. 
Example 5 
The flotation batch was a baryta ore of high sludge content which had the 
following chemical composition with regard to the principal constituents: 
39% BaSO.sub.4 
6.5% Fe.sub.2 O.sub.3 
41.8% SiO.sub.2 
The flotation batch had the following particle size distribution: 
______________________________________ 
&lt;25 .mu.m 
87.2% 
25-40 .mu.m 
10.7% 
&gt;40 .mu.m 
2.1% 
______________________________________ 
A sodium salt of an alkyl ether sulfate based on an adduct of 3 moles 
ethylene oxide with a saturated fatty alcohol mixture having a chain 
length of from 12 to 18 carbon atoms was used as the anion-active 
component while an alkyl polyethylene glycol n-butyl ether based on an 
adduct of 7 moles ethylene oxide with a fatty alcohol mixture having a 
chain length of from 12 to 18 carbon atoms in a weight ratio of 9:1 was 
used as the terminally blocked nonionic surfactant of the invention. 
The tests were carried out in a Denver model D-1 laboratory flotation cell. 
Flotation was carried out at a pulp density of 500 g/l in tapwater having 
a hardness of 16.degree. Gh and at a pH value of 9.5 adjusted by the 
addition of waterglass. The waterglass dosage was 3000 g/t. After rougher 
flotation (for 6 minutes), the concentrate was purified twice. Flotation 
was carried out at 1200 l/minute in every stage. The results obtained are 
shown in Table 4. 
Comparison Example 6 
The flotation batch used was the same as in Example 5. The alkyl ether 
sulfate described in Example 5 was used as collector. The flotation was 
carried out under the same conditions as in Example 5. The results of the 
flotation test are shown in Table 4. 
Comparison Example 7 
The flotation batch was the same as in Example 5. The collector used was a 
commercial collector for the flotation of baryta based on petroleum 
sulfonate. The flotation was carried out under the same conditions as in 
Example 5. The results of the flotation test are shown in Table 4. 
TABLE 4 
__________________________________________________________________________ 
Flotation of baryta 
Flotation 
Total Valuable mineral 
Content (%) 
g/t 
Example stage 
recovery (%) 
recovery (%) 
P.sub.2 O.sub.5 
__________________________________________________________________________ 
200 
Example 5 rt 54.8 1 0.6 
ct 12.9 2 4.8 
conc. 
32.3 97 94.9 
batch 
100.0 100 31.6 
240 
Comparison Example 6 
rt 58.2 1 0.4 
ct 11.2 4 12.1 
conc. 
30.6 95 94.6 
batch 
100.0 100 30.5 
600 
Comparison Example 7 
rt 57.2 3 1.7 
ct 24.6 41 51.6 
conc. 
18.2 56 96.0 
batch 
100.0 100 31.2 
__________________________________________________________________________ 
rt = tailings of rougher flotation 
ct = tailings of purifying flotation (total) 
conc. = concentrate 
The collector combination according to Example 5 enables the collector 
dosage to be reduced by 20% (without any losses in the recovery of baryta) 
compared with the alkyl ether sulfate used alone. 
By comparison, the commercial petroleum sulfonate collector gives only a 
low recovery of baryta despite a considerably higher collector 
consumption. 
Example 6 
The flotation batch was a fluorite ore which had the following chemical 
composition with regard to the principal constituents: 
______________________________________ 
CaF.sub.2 
70% 
SiO.sub.2 
12% 
CaCO.sub.3 
10% 
______________________________________ 
The flotation batch had the following particle size distribution: 
______________________________________ 
&lt;25 .mu.m 
45.2% 
25-63 .mu.m 
29.9% 
63-100 .mu.m 
25.0% 
&gt;100 .mu.m 
0.9% 
______________________________________ 
The collector composition in accordance with the invention contained 
technical grade oleic acid as the anion-active component. The nonionic 
component consisted of a fatty alcohol polyethylene glycol n-butyl ether 
based on an adduct of 5 moles ethylene oxide with one mole of a fatty 
alcohol mixture having a chain length of from 12 to 18 carbon atoms. The 
weight ratio of the anion-active component to the nonionic component was 
7:3. The total collector dosage was 300 g/t. 
The flotation tests were carried out in a laboratory flotation machine 
(Denver Equipment model D-1; 1-liter cell). The pulp density was 500 g/l 
in the rougher flotation and 300 g/l in the purifying flotation. 
Quebracho was used as depressor, its total dosage amounting to 1500 g/t 
administered in three equal parts (500 g/t each) in the 3 stages of the 
purifying flotation. 
The pulp temperature was 30.degree. C. in all stages of the flotation. The 
pH of the pulp was within the range of 8 to 8.5. The conditioning time of 
depressor and collector was 5 minutes in each case. The conditioning was 
carried out at a stirring speed of 1400 r.p.m. Flotation was carried out 
at 1200 r.p.m. The flotation time was 6 minutes. 
The flotation results are shown in Table 5. 
Comparison Example 8 
The flotation batch used was the same as in Example 6. The technical grade 
oleic acid of Example 6 alone was used as a collector, its total dosage 
amounting to 650 g/t. Flotation was carried out under the conditions 
described in Example 6. The results obtained are shown in Table 5. 
TABLE 5 
______________________________________ 
Flotation of fluorite 
Total CaF.sub.2 Concentrate content 
dosage Recovery CaF.sub.2 
Example (g/t) (%) (%) 
______________________________________ 
Example 6 300 88 93.3 
Comparison 
650 89 92.3 
Example 8 
______________________________________ 
The test results in Table 5 show that in using the collector combination in 
accordance with the invention the collector dosage may be considerably 
reduced without a decrease in the recovery of the valuable mineral or in 
the concentrate content. 
Example 7 
The flotation batch consisted of a baryta ore which had the following 
chemical composition with regard to the principal constituents: 
______________________________________ 
BaSO.sub.4 
65% 
Silicates 
20% 
Iron ores 
10% 
______________________________________ 
The particle size distribution of the flotation batch was such that 100% 
were smaller than 75 .mu.m. 
The collector mixture in accordance with the invention contained, as the 
anion-active component, a sodium alkyl sulfate whose alkyl residue was 
derived from a fatty acid mixture consisting essentially of C.sub.16 
-C.sub.18 fatty alcohols. The nonionic component consisted of a fatty 
alcohol polyethylene glycol n-butyl ether based on an adduct of 5 moles 
ethylene oxide with one mole of a fatty alcohol mixture having a chain 
length of from 12 to 18 carbon atoms. The weight ratio of the anion-active 
component to the nonionic component was 6:4. The total collector dosage 
was 350 g/t. 
The flotation tests were carried out in a laboratory flotation machine 
(Denver Equipment model D-1; 1-liter cell). The pulp density was 500 g/l. 
Waterglass was used as a depressor in an amount of 1000 g/t. The pulp had a 
pH of 9 which resulted from the addition of waterglass. Flotation was 
carried out at room temperature with a rougher and a purifying stage, i.e. 
in two stages. The conditioning time of depressor and collector was 5 
minutes each. The flotation time was 6 minutes. Conditioning and flotation 
were carried out at a stirring speed of 1200 r.p.m. 
The results obtained are shown in Table 6. 
Comparison Example 9 
The flotation batch used was the same as in Example 7. The sodium alkyl 
sulfate of Example 7 alone was used as a collector, its total dosage being 
450 g/t. For the rest the flotation of the baryta ore was carried out 
under the same conditions as the ones described in Example 7. The test 
results obtained are shown in Table 6. 
TABLE 6 
______________________________________ 
Flotation of baryta 
Total BaSO.sub.4 Concentrate content 
dosage Recovery BaSO.sub.4 
Example (g/t) (%) (%) 
______________________________________ 
Example 7 350 98 91.6 
Comparison 
450 97 91.3 
Example 9 
______________________________________ 
The test results in Table 6 show that in using the collector mixture in 
accordance with the invention the same BaSO.sub.4 recovery and the same 
BaSO.sub.4 content in the concentrate may be achieved with a considerably 
reduced collector dosage as compared with the conventional sodium alkyl 
sulfate collector. 
Example 8 
The flotation batch was an apatite ore which had the following composition 
with regard to the principal constituents: 
______________________________________ 
Magnetite 
39% 
apatite 18% 
carbonate 
11% 
phlogopite 
14% 
olivine 9% 
______________________________________ 
The particle size distribution of the flotation batch was as follows: 
______________________________________ 
&lt;25 .mu.m 
18% 
25-100 .mu.m 
34% 
100-200 .mu.m 
43% 
&gt;200 .mu.m 
5% 
______________________________________ 
The collector composition in accordance with the invention contained an 
acyl lactylate based on technical grade oleic acid as the anion-active 
component. The nonionic component consisted of an adduct of 5 moles 
ethylene oxide with one mole of a fatty alcohol mixture having a chain 
length of from 12 to 18 carbon atoms. The weight ratio of the anion-active 
component to the nonionic component was 7:3. The total collector dosage 
was 730 g/t. 
The flotation tests were carried out in a laboratory flotation machine 
(Denver Equipment model D-1; 1.2-l cell) at 20.degree. C. Hard water 
containing 945 ppm Ca.sup.2+ and 1700 ppm Mg.sup.2+ was used to prepare 
the pulp. After the ore had been suspended in the flotation cell the 
magnetite was removed with a hand magnet, washed with water and the wash 
water returned to the cell. The pulp density was 500 g/l. Waterglass was 
used as depressor in quantities of 2000 g/t. The pH of the pulp was 
adjusted to 11. Flotation was carried out at a rotational speed of the 
mixer of 1500 r.p.m. The flotation time was 6 minutes. After rougher 
flotation the concentrate was twice subjected to purifying flotation. 
The results obtained are shown in Table 7. 
Comparison Example 10 
The flotation batch was the same as in Example 8. The acyl lactylate of 
Example 8 alone was used as a collector, its total dosage being 900 g/t. 
For the rest the flotation was carried out under the same conditions as 
Example 8. The results obtained are shown in Table 7. 
TABLE 7 
______________________________________ 
Flotation of apatite 
Total P.sub.2 O.sub.5 
Concentrate content 
dosage Recovery P.sub.2 O.sub.5 
Example (g/t) (%) (%) 
______________________________________ 
Example 8 730 80 22.3 
Comparison 
900 83 17.6 
Example 10 
______________________________________ 
The test results in Table 7 show that the collector combination according 
to Example 8 enables the collector dosage to be considerably reduced--in 
comparison with the dosage of the conventional collector of comparison 
Example 8--without decrease of the P.sub.2 O.sub.5 recovery, while 
resulting in an increase on P.sub.2 O.sub.5 content in the flotation 
product.