Method of gold extraction from highly mineralized chloride solutions of potash fertilizers

 

(57) Abstract:

The invention relates to a hydrometallurgical methods for extracting gold from saline solutions formed during processing of fossil-based potash potash fertilizers. The gold content in the solution is 0,010 - 0,100 g/m3. The technical result of the invention is to provide an environmentally safe method of passing the recovery of gold from solutions of potassium fertilizer production, reducing the cost of obtaining gold product suitable for further industrial processing. The method consists in the co-deposition of gold from highly mineralized chloride solutions of potash fertilizers containing polyvalent metals, by correcting the solution to a pH of 5.6 to 4.7, the introduction of the oxidant to the value of the oxidation potential Eh = 10 - 100 mV and photochemical activation for the hydrolytic precipitation of hydroxides of polyvalent metals impurities and co-precipitation of gold. The oxidant used the oxygen in the air supplied by aeration or oxygen obtained by the decomposition of oxygen-containing reagent. Photochemical activation solution spend ult is the use of sunlight. 4 C.p. f-crystals, 1 table.

The invention relates to a hydrometallurgical methods for extracting gold from saline solutions formed during processing of fossil-based potash potash.

Minerals potassium salts contain as impurities polyvalent elements sulfide group and the gold in the form complexes with ions, and elemental colloidal form and organic compounds in the form of humates. In the process of production of potash fertilizers original fossil salt dissolved in hot water. In the resulting brines pass polyvalent impurity elements and including 25 - 30% of the gold that was in the original salts. After extraction of potash brines formed by saline solutions containing these impurities and organic compounds. These solutions are working, and in the process of dissolution of the original salts accumulate in them polyvalent elements and gold. The gold content varies from 0,010 to 0,100 g/m3. A specific feature of the current solutions is a variable value of the redox potential. The instability of the redox properties of the environment associated with the flotation or by crystallization. The result is a large variety of chemical forms of occurrence in the circulating solution as impurities of polyvalent metals, and gold (see RF patent 2109827).

The method for extracting gold from gold-bearing mineralized chloride solutions of potash fertilizers containing polyvalent elements, including the correction of the original solutions with a gold content of not less than 10 mg/m3to a pH of 5.8 to 7.2, the introduction of the reducing agent and the deposition of gold salts, alkali metal dialkyldithiocarbamate acid under stirring, settling and separation of the obtained gold-bearing sediment - concentrate (see ibid.).

The method for extracting gold has several disadvantages. The resulting precipitate of gold is sulfhydryls gold compounds, iron (II) and impurities in their lower valence. But thiocarbamide complexes of gold in the solution is unstable over time due to their oxidation, and to prevent their destruction should be process intensive and costly excess of reagent - dialkyldithiocarbamate sodium.

Thus, the destruction in time thiocarbamide complexes of gold in rankie process performance.

Technical problem on which this invention is directed, is an environmentally safe method of gold extraction from saline solutions of potash fertiliser, reducing the cost of obtaining and loss prevention with final solutions. The problem is solved in that in the method for extracting gold from gold-bearing mineralized chloride solutions of potash fertilizers containing polyvalent metals, including correction of the solution, the introduction of the reagent, mixing, settling of sediment, containing gold, and his Department, according to the invention the correction is carried out to a pH of 5.6 to 4.7, as the reagent is injected oxidant to the value of the oxidation potential Eh = 10 - 100 mV and conduct photochemical activation for the hydrolytic precipitation of hydroxides of polyvalent metals impurities and co-precipitation of gold.

The oxidant used, the oxygen of the air supplied to the solution by aeration or oxygen obtained by the decomposition of oxygen-containing reagent, and photochemical activation is carried out by ultraviolet radiation in a photochemical reactor for 1.5 - 5 h or ptx2">

The source of the circulating saline solutions having AC components that determine the volatility of the values of redox potential and pH of the medium is subjected to correction by the introduction of an oxidant to a pH of 5.6 - 4.7 and shift of the redox potential in the oxidation region to the steady state value of the oxidation potential Eh = 10 - 100 mV. In these conditions present in the mineralized solution of polyvalent metal impurities from recovery salt forms are transferred in the oxidation hydrolyzable form, and then the solution-slurry is subjected to photochemical activation. Under these conditions, molecular oxygen in solution, decomposes the ozone and atomic oxygen. Gold, which in the original saline solution is present mainly in the passive forms in the oxidation process becomes active ionic form and is easily adsorbed and seacadets in the process of flocculation hydrolysis on the surface of hydroxides of iron (III) hydroxide other impurities, silica and other Photochemical activation accelerates the oxidation, hydrolysis and coprecipitation due to the "chain reaction" decay of oxygen to ozone operations oxidation and photochemical activation allows almost completely precipitate the gold and get gold product the content is suitable for use in the metallurgy of gold. In addition to oxygen for oxidation can be used legaliseerimine oxygen-containing compounds, in particular the potassium permanganate. The claimed invention excludes from the process of environmentally harmful components. The method can be implemented with minimal cost, if you use the oxygen of the air and natural sunlight, but even the use of a photochemical reactor and quartz lamps as the source of ultraviolet radiation retains a high economic efficiency of obtaining gold concentrates for further industrial processing. After photochemical activation solution and defend the clarified part is separated from the gold-bearing sediment is one of the known methods of filtration, decantation, etc.

Substantiation of the parameters

With the introduction of the oxidant in highly mineralized gold-bearing solution containing polyvalent metals, alter the redox potential of the system, translating from the recovery area to undergo oxidative reactions of hydrolysis, resulting in the oxidation of compounds of iron, manganese, ASS="ptx2">

If the value of the oxidation potential of less than 10 mV and a pH of no more than 5.6 hydrolysis of the components of the solution, and when exceeding the value of the oxidation potential of 100 mV and a pH of less than 4.7 indicators of hydrolysis of not improving (see table, PP. 1,2).

Photochemical activation intensifies the oxidation of impurities and gold, hydrolysis and co-precipitation of gold on their hydroxides, silica and natural sorbents (clays, organic acids, etc.,).

Depending on the volume of the solution, the intensity of the radiation photochemical activation are within 1.5 - 5 hours Less time does not guarantee the completeness of the completion of the oxidation reaction of gold and polyvalent metals and impurities, respectively, completeness deposition of gold. Increase exposure time for more than 5 h does not improve the process performance.

The method is illustrated by an example.

Example

As initial solution used highly mineralized chloride of gold solution of potash fertilizers, obtained after flotation or crystallization excretion of potassium salts. In a solution with a pH of 5.8 to 7.2, reduction potential Eh = 30 - 150 mV, containing gold 0,010 - 0,110 mg/m3

As can be seen from table, the claimed combination of features allows you from unconventional sources - poor gold production solutions - brines technologies potassium mineral salts - without engaging in the process of environmentally harmful chemicals and require less energy to get Abagtha of vysokomanevrennyh chloride solutions of potash fertilizers, containing polyvalent metals, including correction of the pH of the solution, the introduction of the reagent, mixing, settling of sediment, containing gold, and his separation, characterized in that the correction leads to a pH of 5.6 to 4.7, as the reagent is injected oxidant to the value of the oxidation potential Eh = 10 - 100 mV and conduct photochemical activation for the hydrolytic precipitation of hydroxides of polyvalent metals impurities and co-precipitation of gold.

2. The method according to p. 1, characterized in that the oxidant is used, the oxygen of the air supplied to the solution by aeration.

3. The method according to p. 1, characterized in that as the oxidant use oxygen, obtained by the decomposition of oxygen-containing reagent.

4. The method according to p. 1, wherein the photochemical activation of the solution is carried out with ultraviolet light in a photochemical reactor for 1.5 - 5 hours

5. The method according to p. 1, wherein the source of ultraviolet radiation using solar light.

 

Same patents:

The invention relates to the field of production secondary non-ferrous metals nametallurgicheskie ways, in particular, from scrap metal, waste Nickel-cadmium batteries

The invention relates to the field of integrated utilization of technogenic raw materials, namely waste chemical current sources (CCS) margantsevskogo system, hydrometallurgical methods

The invention relates to ferrous metallurgy and can be used for the recovery of platinum metals from solid intermediates processing of sulphide copper-Nickel ores
The invention relates to ferrous metallurgy, in particular to the processing of discarded lead batteries

The invention relates to the field of metallurgy gallium, and in particular to a method for producing gallium is recovered from geliysoderzhaschih oxides of rare earth metals
The invention relates to the metallurgy of noble metals and can be used for processing of products containing silver chloride, gold, platinum group metals, base elements predominantly water-insoluble residue Perevozchikov refining industries

The invention relates to the refining of precious metals and can be used in the processing of gold-silver alloys

Vacuum apparatus // 2160788
The invention relates to the field of refining non-ferrous metals, in particular to apparatus for the separation of gallium and arsenic in the clearing of secondary raw materials

The invention relates to a process for recovering vanadium from vysokosvetskoy toxins from converting vanadium cast iron monoprocessor, according to which the pulp of the crushed slag before filtration is treated with sulfuric acid, sulfated slag is subjected to oxidative roasting
The invention relates to a process of producing compounds of rare earth elements (REE) by integrated processing of Apatite

The invention relates to the technology of hydrometallurgy of precious metals and can be applied by enterprises, processing of potash ores, for passing the extraction of gold from industrial solutions

The invention relates to the metallurgy of non-ferrous metals and can be used to extract indium from solutions of zinc and lead production

The invention relates to the metallurgy of noble metals and is intended to highlight the metallic palladium from solutions

The invention relates to metallurgy, and more particularly to processes for obtaining vanadium pentoxide from solutions or slurries of calcined vanadium-containing slag monoprocessor

The invention relates to fluoride technology of processing of such raw materials and can be used to produce titanium and micaceous iron pigments of high purity
The invention relates to methods for extracting gold from gold-bearing materials and can be used in the processing of potash ores

The invention relates to the field of hydrometallurgy heavy non-ferrous metals, in particular to the deposition of the last of acidic sulfate solutions and liquid phases of hydrated ferrous slurries in the form of photoactive sulphides, and can be used as in scheme autoclave-oxidative processing of polymetallic ores and concentrates, and collective wastewater from ions of heavy non-ferrous metals

The invention relates to ferrous metallurgy and can be used for the recovery of platinum metals from solid intermediates processing of sulphide copper-Nickel ores
Up!