JPS5930467B2 - scavenger composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel composition comprising an aqueous solution of dialkyl dithiophosphate in which an N-alkyl, O-alkyl thionocarbamate is dissolved in the solution.

There are many organic sulfur compounds and their structures are diverse.

These compounds have various uses depending on their properties.
Typical uses of organic sulfur compounds are for the production of rayon and cellophane, as insecticides, fungicides, and as flotation agents for mineral concentration. Some organic sulfur compounds are water soluble while others are water insoluble. The lack of water solubility is often an impediment to the widespread use of these organic compounds. For many applications, it is desirable to use a mixture of different types of sulfur compounds to enhance their effectiveness. However, the incompatibility of different sulfur compounds and the lack of water solubility of certain sulfur compounds complicate such mixed use efforts. Generally, different types of sulfur compounds are added separately and various operations are required to obtain a homogeneous mixture. In many instances, the performance of the mixture cannot be maximized due to the incompatibility of different sulfur compounds. Alkali metal or ammonium salts of dialkyl dithiophosphates are water-soluble organic sulfur compounds that have been used as flotation agents for mineral concentration for many years.

N-alkyl, O-alkyl thionocarbamates are organic sulfur compounds that are water-insoluble oils and have uses such as flotation agents for mineral concentration. It is inconceivable that these different compound types could be used as a single composition because of their different solubility properties. According to the present invention, about 35
50% by weight of an alkali metal or ammonium salt of dialkyl dithiophosphate and correspondingly about 65% to 50%
For one stable aqueous solution consisting of % by weight water, the volume ratio of the solution to thionocarbamate is about 5:95 to 95:5.
A stable aqueous solution is provided in which sufficient N-alkyl, O-alkyl thionocarbamate is dissolved to achieve a range of .

The solubility of N-alkyl,0-alkyl thionocarbamates in aqueous alkali metal or ammonium salt solutions of dialkyl dithiophosphates is highly unexpected for a number of reasons.

N-alkyl, O-alkyl thionocarbamates are insoluble in aqueous solutions of alkyl xanthates of alkali metals. The above-mentioned thiophosphate is insoluble in allyl amylzantate, which is a water-insoluble oil that has similar uses and properties to thionocarbamates. It has been found that toluene, which is one of the organic solvents, is not miscible with an aqueous dithiophosphate solution at a ratio in which thionocarbamate is miscible. The range of proportions in which the various thionocarbamates can be mixed with the aqueous dithiophosphate solution varies depending on the individual compounds of both types. The force method of the present invention provides an improvement over the force method for recovering copper values from copper-containing ores by foam flotation.

The foam flotation method uses the following aqueous solution as a scavenger to recover copper. An aqueous solution containing about 35 to 50% by weight of an alkali metal or ammonium salt of dialkyl dithiophosphoric acid and correspondingly about 65 to 50% by weight of water is further treated with a sufficient amount of N-alkyl,0-alkyl thionocarbamate. The volume ratio of the dialkyl dithiophosphate solution to the thionocarbamate is in the range of about 5:95 to 95:5, and the scavenger is dissolved in a volume ratio of about 0.001 to about 95:5 per ton of ore. Use in the range of 0.1 lb. The alkali metal or ammonium salts of dialkyl dithiophosphates useful in the present invention have the following general formula: where M is an alkali metal or ammonium ion, R and R' are straight or branched alkyl groups and carbon atoms. Uniquely selected from numbers 2 to 8.

) Typical compounds include sodium diethyl dithiophosphate, sodium diisopropyl dithiophosphate, sodium diisobutyl dithiophosphate, sodium diisoamyl dithiophosphate, 0,0 bis(1,3-dimethylbutyl) sodium phosphorodithioate. and corresponding compounds such as ammonium or potassium salts.

Alternatively, the acid may be referred to as honuphorodithionic acid,
The esters are called 0,0-esters, and the salts are the same as above. All dithiophosphates contemplated for use in the present invention are water soluble. Thionocarbamates useful in the present invention have the following structure.

(However, Bi and R/'' in the formula are each independently selected from a straight chain or branched alkyl group having 1 to 6 carbon atoms.

) Typical compounds include, for example, isopropylmethylthionocarbamate, isopropylethylthionocarbamate, isobutylmethylthionocarbamate, and the like.

The first alkyl group in the nomenclature is attached to an oxygen atom, and the second alkyl group is attached to a nitrogen atom. Alkylthionocarbamic acids are thus identified and their esters determined by the first alkino exposure of the nomenclature. These compounds are also called thion carbamates, but thionocarbamates is a better name due to the tonality. All thionocarbamates used in this invention are water-insoluble oils. In preparing the composition of the present invention, an aqueous solution of a dialkyldithiophosphate is prepared.

It is generally prepared as an approximately 35-70% by weight aqueous solution depending on the solubility limit of the particular dialkyl dithiophosphate salt used. The solubility of the thionocarbamate depends on the concentration of the dialkyl dithiophosphate solution, but is generally at least about 25
Weight%. In preparing the compositions of this invention, an oily water-insoluble thionocarbamate is mixed with a concentrated dialkyl dithiophosphate solution until a solution is formed.

The amount of thionocarbamate used in this mixing is generally such that the volume ratio of dialkyl dithiophosphate solution to the thionocarbamate is in the range of about 5:95 to 95:5. Specific dialkyl of individual thionocarbamates
Because the solubility of dithiophosphate salts in aqueous solutions varies, the maximum concentration of thionocarbamate in the composition varies. Table 1 below shows the solubility of selected thionocarbamates in certain dialkyl dithiophosphate solutions. It is generally desirable to prepare a solution at or near the maximum solubility of the dialkyl dithiophosphate and to which add the thionocarbamate in the amount ratio required for the particular intended use.

Thus, by preparing a highly concentrated dialkyl dithiophosphate, transportation costs are minimized, and processing is simplified as the desired thionocarbamate ratio can be simply diluted when used. . The compositions of the present invention reduce the number of processing steps normally required for co-use, since the two components do not have to be added separately when it is desired to do so.

The present composition also provides the thionocarbamate in the form of an aqueous solution, which has not been previously available. This aqueous form is desirable for many applications that are processed in aqueous form, thereby eliminating problems associated with uniformly dispersing oily thionocarbamates that are inherently insoluble in water. In some instances, the compositions of the present invention exhibit improved performance over the use of the components alone or over the addition of both components separately and simultaneously. Thus, the compositions of the present invention not only reduce the processing steps and handling difficulties normally associated with thionocarbamates, but also exhibit improved performance while overcoming the conventional problems described above. A particular application for which the solutions of the invention are excellent is as a scavenger in the concentration of valuable constituents from ores by flotation.

Mixed solutions of thionocarbamates and dialkyl dithiophosphates are excellent for flotation of metal sulfides, such as flotation of copper, zinc, platinum, nickel, and molybdenite. Thus, the advantages include reduced processing steps through the use of mixed solutions and increased target metal recovery by retaining high grade concentrates. The amount of scavenger used is such as to provide the highest recovery rate of metal while maintaining a high grade of metal.

Generally this amount is about 0.001 to about 0 per ton of ore.
．． It will vary from 1 pound, preferably from about 0.005 to about 0.05 pounds. The amount used will vary depending on the particular ore to be treated, the composition of the scavenger solution, and the processing equipment used. Optimal usage amounts are easily determined by trial. The present invention will now be explained by way of examples, in which all parts and percentages are by weight unless otherwise specified.

Examples 1-12 A series of solutions were prepared using the following components (1), (2) and (3).

(1) Isopropyl methylthionocarbamate (2)
Isobutyl methylthionocarbamate (3) Sodium diisoamyl dithiophosphate compounds (1) and (2)
) was in the form of an oil without a diluent, while compound (3) was in the form of a 35% aqueous solution.

Compounds (1) and (2) were converted into compound (3) in separate examples.
) and the thionocarbamate to dithiophosphate solution were mixed at a volume ratio of 80/20 to 20/80. Examples are as follows. In each example a stable solution was obtained in which the thionocarbamate was completely dissolved.

Examples 13-32 A series of solutions were again prepared using the following ingredients: (1) Isopropyl methylthionocarbamate (2) Isobutyl methylthionocarbamate (5) Diisopropyl
Sodium dithiophosphate (6) 0,0-bis(1,3
-dimethylbutyl) Sodium dithiophosphate (7) Diisobutyl Sodium dithiophosphate Compounds (1) and (2) are in the form of an oil without diluent, and Compound (6)
was in the form of a 35 fl aqueous solution.

Compounds (5) and (7) were in the form of 50 (fl) aqueous solutions. Details of the example are as follows. In each case a stable solution was obtained in which the thionocarbamate was completely dissolved.

Examples 33-36 A series of solutions were prepared containing the following components: (2) Isobutyl methylthionocarbamate (7) Diisobutyl sodium dithiophosphate Compound (2) in the form of an oil without diluent Compound (7) It was in the form of a 50% aqueous solution.

Details of the example are as follows. In each example a stable solution was obtained in which the thionocarbamate was completely dissolved.

Examples 37-40 A series of solutions were prepared using the following ingredients.

(4) Isopropyl ethylthionocarbamate (5)
Sodium diisopropyl dithiophosphate (7) Sodium diisobutyl dithiophosphate compound (4) was in the form of an oil without diluent and compounds (5) and (7) were in the form of a 50% aqueous solution.

Details of the example are as follows. In each case a safe solution was obtained in which the thionocarbamate was completely dissolved.

Example 41 In this example, the compound (4) of the previous example was compared with the compound (4) of Example 1 (
3) was prepared with a volume ratio of 20/80 (25° C.).

A stable solution was obtained and the thionocarbamate was completely dissolved. Comparative Example A A solution of thionocarbamate dissolved in xandate solution was attempted.

The following ingredients were used. Xanthate (all thionocarbamates were in oil without diluent) Mixtures of all xanthate solutions and all thionocarbamates had a two-phase composition in a volume ratio of 40/60 to 70/30 (at 25°C). gave something.

That is, thionocarbamates were not dissolved in the xanthate aqueous solution. Comparative Example B In this example, an attempt was made to prepare a solution by dissolving allyl amylzantate (a water-insoluble oil) in the following dithiophosphate.

25 mixtures were prepared separately in volume ratios ranging from 60/40 to 30,/70.

Two phases were generated in each test. That is, dissolution of xanthate into the aqueous dithiophosphate salt solution could not be obtained. Comparative Example C The method of Comparative Example B was carried out using toluene in place of the xanthate used in Comparative Example B.

Two phases were formed when the volume ratio of toluene to dithiophosphate salt solution ranged from 60/40 to 30/70, respectively. Examples 42-44 An attempt was made to dissolve the following three oily thionocarbamates without a diluent using a 50% aqueous solution of sodium diethyldithiophosphate as a solvent.

Isopropyl Methylthionocarbamate Isopropyl Ethylthionocarbamate Isobutyl Methylthionocarbamate The results of measuring the weight % solubility limit of each thionocarbamate in a dithiophosphate solution at 25°C are as follows.

Example 45 A conventional experimental flotation force method was performed using crushed and finely ground samples of ore containing 0.6% copper (primarily chalcocite) using various scavengers at various levels. Processed with.

The lowest acceptable crude concentrate grade for this ore that can be increased to the final concentrate grade of currently existing equipment is 10% copper. The scavengers used in this example, their usage levels, and the results obtained are shown in Table 2. Various results of copper recovery and copper grade were plotted to demonstrate the advantages of the inventive solution in flotation.

Figure 1 compares the performance of isopropyl methyl thionocarbamate alone with that of isopropyl methyl thionocarbamate and sodium diisobutyl dithiophosphate in the same total amount as above in a 50:50 volume ratio in the form of an aqueous solution of the present invention. shows.

The optimum usage level for isopropyl methyl thionocarbamate alone is about 0.0525 lb/ton of ore, resulting in a maximum copper recovery of about 82.5% and a grade of greater than 10% copper. The optimum usage level for the solution of the present invention is 0.043 lb/ton of ore, and the maximum copper recovery rate is approximately 83.70! ) bronze role 1
Provides quality of 0% or more. FIG. 2 shows a comparison of the performance of sodium diisobutyl dithiophosphate alone with the same inventive solution described with respect to FIG. diisobutyl
The optimal usage level for sodium dithiophosphate alone is approximately 0.0
At 39 pounds/ton of ore, the highest copper recovery is approximately 1 copper grade.
When obtaining 0% or more, it is about 82 (fl). The results for the solutions of the invention are the same as described for FIG. FIG. 3 shows a comparison of the inventive solution described with respect to FIG. The performance when added is shown.

The optimum usage level for the two components added separately is 0.032 lb/ton of ore and the copper recovery is about 80.9% to obtain a copper grade of about 10% or higher.

The solution of the present invention is as described in connection with FIG. As can be seen in Figure 1, the performance of the solutions of the present invention relative to thionocarbamates alone is at a minimum acceptable for higher copper recoveries at lower effective dosages than obtained with thionocarbamates alone. Indicated by copper grade.

The performance of the solutions of the present invention also shows higher copper recovery at the lowest acceptable copper grade than dithiophosphate alone, as shown in FIG.

The solution of the present invention exhibits higher copper recovery at the lowest acceptable copper grade than when the two components are added separately, as shown in FIG. Comparing the case of adding the two components separately in FIG. 3 with the case of using thionocarbamate alone as shown in FIG. 1, it can be seen that better results can be obtained with thionocarbamate alone.

Similarly, when comparing the case where the two components are added separately (Fig. 3) and the case where dithiophosphate is used alone (Fig. 2), it can be seen that the latter gives better results. Thus combination in aqueous solution shows better performance than the use of other additives. This is another unexpected feature of the present invention. Example 46 Copper-molybdenum ore containing 0.4% copper and 0.04% molybdenum was ground with water to form fines for flotation.

This ore valve is placed in an experimental flotation machine and lime is added to adjust the pH.
lO. Adjusted to 8. Add scavenger to the ore and condition for 1 minute. A total of 0.06 pounds/ton ore of methyl isobutyl carbinol and a mixture of C6 and C8 alcohols are added as foaming agents. Air is introduced and foam is removed for 5 minutes at a constant deslagination rate. Copper and molybdenum in the obtained crude concentrate were analyzed, and the weight percentage of the recovered crude concentrate was measured. Four tests were conducted using the force method described above, each time evaluating a different scavenger.

Table 3 shows the scavengers used and the results obtained. Example 4
7 A series of other scavengers were evaluated according to the method of Example 45.

Table 4 shows the types of scavengers used and the results.
Example 48 In accordance with the force method of Example 45, another series of scavengers were evaluated.

The scavengers used and the results obtained are shown in Table 5. The results of Examples 46-48 further demonstrate that thionocarbamate and dithiophosphate solutions are useful in obtaining optimal recovery of valuable metals.

However, it is necessary to carry out sufficient tests to select the appropriate combination for the ore to be treated.

[Brief explanation of the drawing]

When the dithiophosphate and thionocabamate mixed aqueous solution of the present invention is used as a collecting agent when recovering copper from copper ore by the flotation method, the level of use of the collecting agent, copper recovery rate, and copper grade were compared with other methods. The results of comparison with the scavenger are shown in Figures 1 to 3.

Claims (1)

[Claims] Primary formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (where M is an alkali metal or ammonium ion; R and R'
represents an alkyl group having 2 to 8 carbon atoms in a solution containing 35 to 50% by weight of dialkyldithiophosphoric acid and correspondingly 65 to 50% by weight of water. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(
where R'' and R'' represent an alkyl group having 1 to 6 carbon atoms), the volume ratio of the alkyl dithiophosphate solution to the thionocarbamate is 30:70 to 9
A scavenging agent composition useful in a foam flotation method for recovering copper valuables from copper-containing ore, characterized in that it is dissolved in a sufficient amount to be in the range of 5:5. Secondary formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (1) (where M is an alkali metal or ammonium ion; R and R'
represents an alkyl group having 2 to 8 carbon atoms in a solution containing 35 to 50% by weight of dialkyldithiophosphoric acid and correspondingly 65 to 50% by weight of water. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(
where R'' and R'' represent an alkyl group having 1 to 6 carbon atoms), the volume ratio of the alkyl dithiophosphate solution to the thionocarbamate is 30:70 to 9
A collection agent composition useful in the foam flotation method for recovering copper valuables from copper-containing ore by dissolving it in a sufficient amount to be in the range of 0.001 to 0.5% per ton of copper ore.
A method for recovering copper valuables from copper ore by foam flotation, characterized in that it is used as a scavenger in an amount of 1 pound.