FI75508C - FLOTATIONSMEDELKOMBINATION OCH FOERFARANDE FOER FLOTATION AV MALM. - Google Patents

Description

75508

The present invention relates to a method for recovering minerals by foaming. In particular, this invention relates to a novel composition comprising two or more foaming agent components. Another aspect of the present invention is directed to an ore flotation process, in particular an ore flotation process in which iron, copper, lead or zinc are recovered.

Flotation processes are known and are used to recover and enrich minerals from ores. In flotation enrichment processes, the ore is crushed and wet-milled to produce a slurry. Additives such as mineral aggregates, flotation agents, presses, stabilizers, etc. are added to the slurry to facilitate the separation of valuable materials from the undesired side rock portions of the ore in subsequent flotation steps. The slurry is then aerated to provide foam to the surface. The minerals adhering to the bubbles or foam are peeled or otherwise removed and the mineral-containing foam is recovered and further processed to recover the desired minerals. Typical mineral blowing agents are xanthates, amines, alkyl sulfates, arenesulfonates, dithiocarbamates, dithiophosphates and thiols.

Although ore flotation technology has already reached a significant stage of development, it is an ongoing goal of the ore recovery industry to increase the productivity of ore flotation processes and, above all, to provide specific processes that are selective for one ore or metal and other ores or metals present in the material.

It is therefore an object of the present invention to provide a novel mixture useful in ore flotation.

I.

Another object of the present invention is to provide a foaming process.

It is a further object of the present invention to provide an improved flotation process using a novel alloy to recover iron and / or copper and lead and / or zinc from metal-bearing ores; especially sulfide ores.

These and other objects, advantages, details, features and embodiments of the invention will be apparent to those skilled in the art from the detailed description of the invention and the appended claims.

According to the present invention, it has now been found that a mixture containing n-butyl alkali metal trithiocarbonate to be defined and a lower alkyl alkali metal trithiocarbonate together form a new mixture which is particularly useful as a flotation and aggregating agent in the recovery of iron and / or copper as well as lead and / or zinc. .

According to a first embodiment of the invention there is thus provided a novel composition of matter comprising and preferably consisting of a substantial amount of each of the following compounds: (a) the first compound is an alkali metal n-butyl trithiocarbonate of formula

S

II

M-S-C-S-CH2-CH2-CH2-CH3 wherein M is sodium or potassium, or a mixture of these compounds, (b) the second compound is an alkali metal alkyl trithiocarbonate of formula

S

II

M-S-C-S-R

wherein M is sodium or potassium and R is ethyl, n-propyl or isopropyl or is a mixture of two or more such compounds.

3 75508

The preferred mixture contains the substances defined above as sodium salts, i.e. M is sodium in the preferred blowing agent.

The ore blowing agent of the present invention contains the above ingredients, preferably in the following relative amounts: (a) 50 to 98% by weight of the first compound or mixture, (b) 50 to 2% by weight of the second compound or mixture, the weight percentages being calculated for the first and second of the total weight of the mixture, which together make up 100% by weight.

The blowing agent of this invention is generally used as an aqueous solution. The preferred composition of such an aqueous solution of blowing agent is as follows: 60 parts by weight of water 20 to 39.2 parts by weight of the first compound or mixture, 20 to 0.8 parts by weight of the second compound or mixture.

The ore blowing agent of the invention may further be mixed with blowing agents, presses and stabilizers, as described above. These additives are used in the amounts commonly used in the art. Examples of blowing agents that can be used in addition to the bulking compositions defined above are polyoxyalkylene glycols and ethers having a very wide molecular weight of between 400 and about 1000, and preferably between about 420 and 780. In particular, polypropylene glycols having molecular weights can be used. are, for example, 400, 425, 750 or 900. Polybutylene glycol and polypentylene glycol are also useful substances. Examples of other blowing agents that can be used include methyl, isobutylcarbinol, pine oil, alcohols, phenols, fatty acids and cresylic acid.

Printers that can be used in conjunction with the bulk compositions defined above include sodium cyanide, sodium sulfide, 75508 4 lime, zinc sulfate, starch, glue, and sulfuric acid, among others.

Both the n-butyl trithiocarbonate mixture and the lower alkyl trithiocarbonate mixture are present in the ore blowing agent of this invention in substantial amounts. Although the preferred weight ranges are given above, the term "substantial" as used herein means the amount of each mixture that is so large that it alters or modifies at least one flotation process parameter compared to using only another mixture of blowing agent. A "substantial" amount of each mixture is present, especially if the recovery of a particular ore achieved by the combination of substances is greater than the recovery activity or efficiency of the other substance alone.

The first alloy is alkali metal n-butyl trithiocarbonate as defined. Most preferably, it is sodium metal n-butyl trithiocarbonate. Said first ingredient may also be a mixture of sodium and potassium n-butyl trithiocarbonate.

Another mixture present in the blowing agent of this invention is an alkali metal C 2-3 alkyl trithiocarbonate. In the blowing agent of the invention, the sodium salt is most preferred. Isopropyl alkali trithiocarbonate is particularly preferably used for foaming iron and / or copper. n-propyl alkali metal trithiocarbonate and ethyl alkali metal trithiocarbonate as well as mixtures of the two components are particularly suitable for flotation of lead and / or zinc ore.

According to another embodiment of the present invention, a flotation method is provided. This flotation method comprises the steps of (a) mixing the mineral with water and a mixture as defined above to provide a slurry, (b) aerating the slurry to provide a foam and a residual product;

II

75508 (c) separating the foam and the residual product and (d) recovering minerals from the foam and / or residual product thus separated.

These process steps are conventional except for the new mixture used as a collector as defined above. Although both mixtures can be added separately during flotation and added to either the mineral grinding step or flotation, it is preferred that the ingredients be premixed, blended, or otherwise combined prior to use.

The composition of the invention is useful for a variety of minerals.

However, the mixture is particularly useful for recovering valuable minerals from sulfide ores.

To recover iron and / or copper from such minerals, the isopropyl trithiocarbonate salt is particularly useful in combination with the n-butyl trithiocarbonate salt.

For the recovery of lead and / or zinc, the ethyl and n-propyl trithiocarbonate salts (or both) together with the n-butyl trithiocarbonate salt have proven to be advantageous.

The total amount used for both of the above-defined kckooja compounds or mixtures is generally about 2 to 230 g / tonne of ore (or tonne of concentrate or other mining deposit in question).

Examples of ores to which the flotation of this invention and the process of this invention can be applied are listed below:

Copper ores:

Covellite CuS Valerite Cu2Fe4S7 or

Cu3Fe4S7

Chalcosite Cu2S Cupritite Cu20

Chalcopyrite CuFeS2 Tenorite CuO

Bornite Cu, -FeS4 Chrysococcal CuSiOg

Cubanite Cu2SFe4Sg Bournonite PbCuSbS ^ 6 75508

Leaded ores:

Galeena PbS

Zinc-bearing ores:

Sphalerite ZnS

Zincite ZnO

Smithsonite ZnCO 2

Ferrous ores;

Magnetite FeO, Fe2 ^ 3

Pyrite FeS

Pyrrotite Fe5S6 “Fe16S17 * '* According to another embodiment of the present invention, it has been found that the yield of iron and copper is very high when a blowing agent containing a substantial amount of each of the following ingredients is used: (a) a first compound of formula

S

II

M-S-C-S-CH2-CH2-CH2-CH3 wherein M is sodium or potassium, or a mixture of these compounds, (b) another compound of formula

S

m-s-H-o-c5hi; 1 wherein M is sodium or potassium, or a mixture of both.

Alkali metal n-butyl trithiocarbonate and alkali metal amyl xanthate are preferably used in the following weight ratios: 16 to 24 parts by weight of the first compound 84 to 76 parts by weight of the second compound

The combined total weight of the first and second compounds is 100 parts by weight.

A blowing agent according to another embodiment of the present invention

II

7 4 75508 is also prepared and preferably used as an aqueous solution. As such, the substance contains (a) 60 parts by weight of water, (b) 8 to 15.7 parts by weight of the first compound, (c) 32 to 24.3 parts by weight of the second compound which is said xanthate.

The present invention also relates to a flotation process using a flotation agent according to another embodiment of the present invention. For this embodiment, the preferred conditions and steps for the blowing agent are substantially the same as described above, except that the blowing agent used is a blowing agent containing trithiocarbonate and xanthate as defined below. This process is particularly suitable for recovering iron and / or copper from a mineral containing these precious metals, in particular sulphide minerals.

The invention is described in more detail below by means of examples which show preferred embodiments of the invention.

Example I

This example describes a typical procedure used here to evaluate ore blowing agents. An example comprises an inventive run in which trithiocarbonate is used in combination with a known xanthate type mineral collector and a comparison with a run in which two known mineral collectors, xanthate and dithiophosphate, are used. To the ball mill was added 1100 g of iron, copper-containing ore (Disputada ore, Chile) together with 1000 ml of tap water and 2.5 g of lime and the mixture was ground for 5.5 min. The slurry was transferred to a 2.5 L Denver D-12 flotation cell along with enough water to fill the cell 2.5 cm from the lip (approximately 35% by weight aqueous solids). 1 drop of foaming agent (methyl isobutyl carbonol), 32 g / t sodium di-sec-butyl dithiophosphate (AC238, American 75508 8) was also added to the cell with stirring at 100 rpm.

Cyanamide) and 26 g / t potassium amyl xanthate (Z-6). The mixture was cured for 1 minute and foamed for 10 min. The foamed concentrate was filtered, dried and analyzed. The procedure was repeated except that instead of the AC238 and Z-6 collector combination, a collector combination of 26 g / t potassium amyl xanthate (Z-6) and 32 g / t sodium n-butyl trithiocarbonate was used. The results shown in Table I show that the mixture according to the invention, potassium amyl xanthate and sodium n-butyl trithiocarbonate, gives an increase in iron and copper recoveries.

Table I

Effect of aggregate mixtures on percentage _ recovery__ 1100 g ore Percent

Driving Recovery No. _Collector (58 g / h) _ Fe Cu

Comparison:, 1 54.6% dithiophosphate + 45.4% xanthate 41.11 80.47 2 54.6% dithiophosphate + 45.4% xanthate ^ 44.38 77.54

Average = 42.75 79.01

The invention; .3 54.6% tritic carbonate + 45.4% xanthate 0 43.39 79.91 4 54.6% trithiocarbonate + 45.4% xanthate 13 45.81 80.40

Mean = 44.60 80.16 αAC-238, sodium di-sec-butyl dithiophosphate (1% aqueous solution).

° Z-6, potassium amyl xanthate (1% aqueous solution).

C1% aqueous sodium n-butyl trithiocarbonate solution.

Example II

This example illustrates the efficiency of combining two different trithiocarbonates as a collector. The procedure described in Example I was repeated except that * sodium isopropyl trithiocarbonate and sodium n-butyl trithiocarbonate were used as collectors. The results in Table II show an increase in the percentage recovery of iron and copper when sodium sorpropyl trithiocarbonate and sodium

II

75508 9 n-butyl trithiocarbonate is used together, compared to using each collector separately. The values appear to indicate a more or less constant percentage recovery in copper when the concentration of isopropyl trithiocarbonate is varied with respect to the butyl trithiocarbonate concentration, but the percentage recovery of iron increases with increasing isopropyl trithiocarbonate concentration.

Table II

Effect of trithiocarbonate mixtures on percentage recovery of 1100 g of ore

The percentage

Driving recovery_ No. __ Collector (58 g / t) _ Fe Cu

Comparison: 1 Isopropyl TTC® only 34.72 64.84 2 Isopropyl TTC® only 30.21 61.16

Average = 32.47 63.0 3 n-butyl TTC * 3 only 38.71 76.85 n-butyl TIU * 3 only 36.85 73.69

Mean = 37.78 75.27

Invention c: 5.9% isopropyl TTC + 94.1% n-butyl ITC 44.94 79.31 6 5.9% isopropyl TIC + 94.1% n-butyl TIC 40.86 78.76

Average = 42.90 79.0 7 11.1% isopropyl TTC + 88.9% n-butyl ITC 48.37 82.63 8 11.1% isopropyl TTC + 88.9% n-butyl TTC 47.39 77 , 98

Average = 47.88 80.31 9 20.0% isopropyl TTC + 80.0% n-butyl TTC 49.00 80.25 10 20.0% isopropyl TTC + 80.0% n-butyl TTC 46.24 75 , 86

Average = 47.62 78.01 11 25% isopropyl TTC + 75% n-butyl TTC 53.37 82.94 12% 25% isopropyl TTC + 75% n-butyl TTC 48.35 77.48

Mean = 50.85 80.21 ®Natriumium propyl trithiocarbonate (1% aqueous solution) prepared from isopropyl mercaptan, CS, NaQH, water in Ind. & Eng. Chem. Butter. 42, p. 5 according to the general method described.

Atrium n-butyl trithiocarbonate (1% aqueous solution) prepared from n-butyl imercaptan, CS 2, NaOH, water according to reference a.

The tritric carbonate mixtures were prepared in the same manner as described using a corresponding mixture of, for example, 25% isopropyl mercaptan and 75% n-butyl mercaptan and CH 2 Cl 2 in NaOH in water.

10

Example III 75508 This example illustrates the effectiveness of combining sodium n-butyl trithiocarbonate with another type of alkyl trithiocarbonate, such as sodium ethyl trithiocarbonate. The general procedure described in Example I was repeated, but using different types of ore (i.e., Pb, Zn, Fe-containing) and a different collector system (sodium ethyl trithiocarbonate in combination with n-butyl trithiocarbonate). The results shown in Table III below show that during Pb foaming, the combination of n-butyl trithiocarbonate with ethyl trithiocarbonate (runs 5, 6) increases lead recovery compared to using each collector separately (runs 1, 2 and 3, 4 ). The values also show that the premixing of ethyl and butyl trithiocarbonates (runs 7, 8) is comparable in terms of percentage recoveries (Pb, Zn, Fe) to adding collectors only to the cell together (runs 5, 6). In addition, the values indicate that butyl trithiocarbonate itself gives an undesired increase in zinc and iron during the first flotation (Pb).

li 11 75508

Table III

Effect of tritium carbonate mixture on percentage recovery of lead, zinc, iron (1000 g Ozark nialm, 350 ml water, 0.35 kg / t zinc sulphate, 45 g / t NaCN, 13 g / t isobutyl carbonol standard diluent, powder diluted 35%: in the flotation cell, collector added, flotation 5 min)

The percentage

Driving Recovery No. _Kccollector (4 g / h) ______ pb_ Zn Fe

Comparison: 1 n-butyl-i-TDCa alone 74.9 53.3 6.32 2 n-butyl-i-TTCa only 84.5 49.7 6.63

Average = 79.7 51.5 6.5 3 Ethyl-TTC ^ only 70.4 10.9 3.64 4 Ethyl-TIC * 3 only 80.8 13.6 1.71

Mean = 75.6 12.3 2.7

Invention: 5 50% n-butyl-TIC + 50% ethyl-TIC 78.6 25.6 5.97 6 50% n-butyl-TDC + 50% ethyl-TTC 84.9 19.3 4, 66

Mean = 81.8 22.5 5.3

7 Premixed mixture 50% n-butyl-TTC

+ 50% ethyl TTC 80.0 18.5 4.65 8 Word as 7 84.5 26.4 5.09

Mean = 82.3 22.5 4.9 aSodium n-butyl trithiocarbonate in 40% aqueous solution, sodium sodium trithiocarbonate in 40% aqueous solution.

Claims (10)

75508 Foaming agent, characterized in that it contains a) at least one alkali metal n-butyl trithiocarbonate of the formula IS MSCS-CH 2 -CH 2 -CH 2 -CH 3 (I) in which M is sodium or potassium, and b) at least one alkali metal alkyl trithiocarbonate of formula 11 S II MSCY (II) wherein M is sodium or potassium and Y is SR, wherein R is ethyl or n-propyl. Foaming agent according to Claim 1, characterized in that it contains 50 to 9% by weight of X component a) and 50 to 2% by weight of X component b>, the weight Xs being based on 100% by weight of components a) and b). to the combined total weight, wherein M is preferably sodium. Foam mixture according to Claim 1 or 2, characterized in that it further contains water, in particular 100 parts by weight of water, 20 to 39.2 parts by weight of component a), and 20 to 0.6 parts by weight of component b. ). A flotation method, characterized in that 1. a mineral material, preferably crushed ore, water and a blowing agent mixture according to any one of claims 1 to 3, is mixed to obtain a slurry, 2. a slurry is aerated to produce a foam and a residual product, II 13 75508 3. a foam and a residual product are separated, and 4. recovering valuable minerals from the foam and / or residual product. Process according to Claim 4, characterized in that the mineral is a sulphide ore or a mineral derived or recovered from the sulphide ore. A method according to claim 4, characterized in that the blowing agent is added to the mineral powder. A method according to claim 4, characterized in that said blowing agent mixture is added to the flotation. Θ. Process according to Claim 5, characterized in that iron- and / or copper-containing minerals are used. Process according to claim 4, characterized in that sodium n-butyl trithiocarbonate and sodium isopropyl trithiocarbonate are used together for flotation with a flotation process to recover copper from said mineral. Process according to Claim 5, characterized in that sodium n-butyl trithiocarbonate and sodium ethyl trithiocarbonate and / or sodium n-propyl trithiocarbonate are used in a flotation process to separate and recover valuable lead and / or zinc from lead- and / or zinc-containing mines. 75508