US1833740A - Process of ore flotation - Google Patents

Description

' Patented Nov. 24, '1931',

j -UNITED STATES PATENT O I IRA E. DERBY AND cam 13. CUNNINGHAM, or INDIANAPOLIS, INDIANA, As'sIeNons no PETER c, REILLY, or INDIANAPOLIS, INDIANA rnocnss or ozan ILorA'no'N No Drawing.

The present invention relates to the froth flotation of ores, other metalliferous materials, by the useof certain classes of tri-thiocarbonate compounds as hereinafter discussed, The invention is based on the use of the mono-ester acids or their alkali oralkaline earth metal salts. Thus the salts of mono-ethyl tri-thiocarbonic acid (or of other mono-alkyl or mono-aryl tri-thiocarbonic acids) or the acids themselves constitute excellent collecting agents for use in flotation. These compounds can be prepared, for example, by reaction of mercaptans, carbon bisulfide, and caustic alkali or sodium sulfidex We give the following Classification of the tri-thiocarbonate type of compounds WhlCh can be conveniently employed in flotation in accordance with the present invention: (a)

the acid esters of tri-thiocarbonic acid, including the alkyl .and the aryl derivatives such as, for example, the mono-ethyl ester, the mono-propyl ester and the mono-phenyl derivative (b) the metallic salts of the mono? ester acids of tri-thiocarbo'nic acid such as, for example, the sodium, potassium or barium salts of mono-ethyl tri-thiocarbonic acid;

(a the ammonium salts of the mono-ester aclds of tri-thiocarbonic acid such as, for example, ammonium ethyl tri-thiocarbonate; (d) the salts of the mono-ester acids of trithiocarbonic acid formed with nitrogenous bases, such as, for example, the mono ethyl' tri-thiocarbonate salts of hydroxylamine or (In these salts the nitrogenous ase, which is a substituted ammonia, may be considered as functioning somewhat like a metal in the compound, the reaction bein analogous to the reaction of ammonia witfi an acid to form ammonium salts;)

The substances above "referred to come within the generic formula KsM' in which B may represent an alkyl or aryl radical, and M may represent an inorganic radical (such as the ammonium radical), alkali or alkaline earth metal, hydrogen, or substituted ammonium complex (for example that obtained by the reaction of a nitrogenous including sulfid ores, and

Application filed March 19, 1926. Serial No. 96,062,

base with a tri-thiocarboni'c acid compound. The characters M and R are used in this sense hereinafter,

In order to make ourselves entirely clear,

We will state that the tri-thiocarbonic acid is a well known substance having the formula CS (SH) Ethyl tri-thiocarbonic acid (which can be called hydrogen mono-ethyl tri-thiocarbonate), is likewise a well known substance, having the formula SC H CS-= SH. \Vhile these substances are more or less well known, having been described in text books of chemistry for many years, they do not seem to have heretofore been employed or suggested for employment in the art of mineral flotation. According to our researches, these substances are active flotation agents, and the salts of the a1kyl-tri-thiocar; bonic' acids are found to be especially active: An illustrative example would be C H S- 'CS-- -SK. While these substances have great selective action or collecting power for sulfid minerals, in the flotation operation, they do not have any substantial frothing properties, so that an appropriate frothing agent such as pine oil should be employed iniconjuncti'on therewith, in carryingout the froth flotation operation.- In carrying out the flotation operation it is preferable to use either a neutral or alkaline circuit depending on the character of the ore. In an acid circuit the salts of the acid ester tri-thiocarbonate compounds are unstable, the degree of instability depending 'on the acidity of the circuit and on theparticular compound used. ,A sli htly acid circuit can be successfully use however, if suificient reagent is added to take care of the loss due to decomposition duringthe flotattion operation, for example, an acidity of fifteen hundredths per cent (0.15%) of sulfuric acid was successfully used with sodium ethyl tri-thiocarbonate on a copper sulfide ore by doubling the amount of reagent employedwith the same ere in a lime circuit.

As a specific example of the process,.tov

which the invention of the present case 1s not restricted, the following isgiven An ore containing copper-sulfid wasmade into a pul withwater, and an amount of sodium et yl tri-thiocarbonate was added equivalent to one-tenth of a pound (0.1 lb.) of this material to a ton of the dry ore. An amount of pine oil was then added, .as a frothing agent, equivalent to .22 lb; per ton of ore, and 4 lbs. of hydrated lime was added and the miXture'was then subjected to aeration flotation, in a Janney machine of the ordinary construction.- We were able in this manner to separate a high grade concentrate, and-to leave a tailing containing practically no cop-per.

The quantity of tri-thiocarbonate compound to be used in the flotation operation may be varied, depending upon the specific ore under treatment andother'factors. -We find that from five hundredths (0.05 lb.) pound to two pounds (2 lbs.) or more of trithiocarbonate compound per ton of dry ore can be used successfully in floating ores of this character.

It will be understood that the tri-thiocarbonate compound can be used as the sole or essential selecting or collecting agent, or it can be used in conjunction with various oily materials, such as are shown in the art for this purpose. The tri-thiocarbonate compound, either alone or with other flotation.

agents can be incorporated with the ore while the same is being wet-ground, for example in a tube mill. In other modifications, the ore can be ground Without the addition of the tri-thiocarbonate or oily flotation or frothing agents,'and these can subsequently be dissolved or emulsified and-added to the water with which'the pulp is to be formed, or the tri-thiocarbonate can be added to the pulp of ore and water and dissolved or emulsified therewith. The order of adding the ore, water and flotation agent and frothin agent, accordingly can be varied to suit the particular ore under treatment orto suit the conditions of the plant in which the operation is to be conducted.

What is claimed is:

1. A process which comprises subjecting me-talliferous material to'a froth flotation treatment while. associated with a tri-thioin which M represents hydrogen or a metal carbonate substance containing one hydrocarbon radical only replacing a hydrogen ,atom of the tri-thiocarbonic acid.

2. Froth flotation of material in the pres- "ence of an agent including a tri-thiocarbonate of the type Sulphalkyl o M or an inorganic radical acting as a metal or a substituted ammonium complex.

3. The step of froth flotation of material in the presence of an agent including a trithiocarbonate of the type l SCzHs s=o I in which M represents'a hydrogen or a metal or an inorganic radical acting as a metal or a substituted ammonium complex.

4. In the process of concentrating ores and minerals by flotation, the step which comprises subjecting the ore in the form of a pulp to a froth flotation operation in the presence of an alkali metal salt of monoethyl tri-thiocarbonic acid.

. 5. In the process of concentrating ores and minerals by flotation, the step which comprises subjecting the ore in the form of a pulp to a froth flotation operation in the presence of a derivative of tri-thiocarbonate having the following structural formula:

in which R is an alkyl or aryl group and M is an alkali metal.

'6. In the art of concentrating ores, the

herein described step which comprises subjecting the ore to froth' flotation in the presence of a compound containing the radical consisting of me'tals, hydrogen, and radicals functioning. as a metal.

8. In the process of concentrating ores and minerals by flotation, the step which comprises subjecting the material to be concentrated in the form of a pulp to a froth flotation operation in the presence of an organic-inorganic derivative of tri-thiocarbonic acid having the structural formula:

in which R is an 'alkyl or aryl group and M represents hydrogen or a metal-or an inorganic radical acting as a metal or a substi- 1 tuted ammonium complex.

9. In the process of concentrating ores and minerals by flotation, the step which comprises subjecting the ore in the form of a pulp to a froth flotation operation in the presence of an organic-inorganic derivative of tri-thiocarbonic acid having the following structural formula:

where R represents a hydrocarbon radical and M represents metal, hydrogen, or a radical functioning like a metal.

'10. In the process of concentrating ores and mmerals by flotation, the step which comprises subjectin ithe same in' the form of a pulp to a frot flotation operation in the presence of a derivative of tri-thiocarbonic acid having the following structural forin which R is an 'alkyl or varyl group and M is a metal hydrogen or an inorganicradical 11. In the 'process of concentrating ores and minerals by flotation, the step which comprises subjectin the ore in the form of a pulp to a froth otation operation in the presence of an alkali. metal salt of monoethyl tri-thiocarbonic acid.

12. A process of flotation in the presence of an agent including a tri-thiocarbonate of the type in which M represents hydrogen or a metal or an inorganic radical acting as a metal or a a substituted ammonium complex.

25 13. In the process of concentrating ores and minerals by flotation, the step, which comprises subjectin the same in the form of a pulp to a froth otation operation in the presence of a nitrogenous base salt of a mono- Y 30 ester of a tri-thiocarbonic acid.

14. In the process of concentrating ores \and minerals by flotation, the step,- which comprises subjecting the same in the form of pulp to a froth flotation operation in the presence of a pyridine base saltof a mono 35 ester'of tri-thiocarbonic acid'..-

In testimony whereof we have signed our names to this specification. 1 r 1 IRA'H. DERBY. ORIN D. CUNNINGHAM.