A pretreatment method for refractory metallurgical concentrates (2)

The invention has low reaction pressure, so the equipment requirements are not high, and there is no safety difficulty; since the reaction temperature can be designed to be high, the treatment effect is superior to the method used abroad; since only low-priced sulfuric acid is usually used for the reaction. The medicament is not too large, so the treatment cost is low; after the reaction, it only needs to be washed to neutral to be sent to the cyanide chemical section, so the process is not long, and the equipment is not complicated compared with other methods, according to the mine. The conditions can be either batch production or continuous production.

Due to these advantages, the method of the present invention will be widely used.

three Patent requirements:

(1 ) A pretreatment method for gold concentrates (including ore) difficult to be smelted, characterized in that sulfuric acid is used as a chemical reaction agent;

2 according to patent claim 1 , which is characterized in that the concentration of sulfuric acid used in the reaction is not limited, and when concentrated sulfuric acid is used, the energy consumption of the reaction is low;

3 According to patent claim 1 , it is characterized by a chemical reaction temperature of 200~ 400 °C Scope; 4 according to patent claim 1 , characterized in that the reaction pressure is normal pressure, the maximum does not exceed 0.3Mpa ;

5 According to patent claim 1 , the reaction time does not exceed 4 hours;

6 According to the patent claim 1 , the weight ratio of sulfuric acid (converted to concentrated sulfuric acid) to the material to be treated is in the range of 0.1 to 2 : 1 , which is related to the content of reducing substances in the raw materials;

7 according to claim 1 , characterized in that only the oxidation of sulfuric acid at high temperature is utilized during the reaction, and oxygen or oxygen in the air is not required to participate in the reaction;

8 According to the patent claim 1 , the reactor may be pressurized or unpressurized, or other types of equipment may be used, such as a reaction apparatus similar to a drying kiln.

four Example

Tests gold concentrate containing arsenic from Liaoning a mine, gold grade of 55.8 g / t, silver 217g / t, 3.15% arsenic, 16% sulfur, 18% iron-containing carbonaceous 3.45% .92% of sub-microscopic gold, pyrite gold wrapped 19.4%, proportion of the gold wrapping arsenopyrite 68.57%.

It was treated by biochemical decomposition method at 18% pulp concentration for 170h , and then cyanidation leaching, the leaching rate was 95% .

Direct cyanidation leaching for 24 hours, and the cyanation conditions were the same as in the examples. The gold concentration of the leachate was 0.52 mg/l , and the gold leaching rate was only 18% .

Example 1

take 10g The mixture was placed in a 150 ml self-made stainless steel reaction vessel, 5 ml of concentrated sulfuric acid was added , and after stirring uniformly, the gold fine powder adhered to the stirring bar was flushed into the reaction vessel with water, and the lid was closed. Put the reaction kettle in an incubator and warm it to set the reaction temperature. 275 °C At a constant temperature for 1 hour, then naturally cooled to room temperature, flushed into a beaker with water and washed several times with water. When the pH of the wash water rises to 7 , add 50 ml of 1% sodium cyanide solution, add water to nearly 200 ml , add 2% concentration. the caustic soda solution minor adjustments to the pH of the slurry reached about 10, supplemented with water to 200ml, with occasional stirring. after 24 hours, the concentration of the gold leaching solution 2.76mg / l, an amount of 195ml leaching solution by calculation, the leaching rate of 96%.

Example 2

10g Gold fine powder, treated according to the procedure of Example 1 , the reaction temperature is 250 °C The reaction was kept at a constant temperature for 2 hours, and the remaining conditions were unchanged. The gold concentration of the leachate was 2.14 mg/l , and the gold leaching rate was 74.8%.

Example 3

10g Gold fine powder , treated according to the procedure of Example 1 , the reaction temperature is 270 °C The reaction was kept at a constant temperature for 2 hours, and the remaining conditions were unchanged. The gold concentration of the leachate was 2.63 mg/l , and the gold leaching rate was 91.9% .

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