What is the general content of the gold leaching test?

Grinding fineness test

The surface of the gold monomer dissociated or exposed gold is a necessary condition for cyanide leaching or new non-toxic leaching, so appropriately increasing the fineness of the grinding can increase the leaching rate. However, over-grinding not only increases the grinding cost, but also increases the possibility of leachable impurities entering the leachate, resulting in the loss of cyanide or immersion gold and dissolved gold. In order to select a suitable grinding fineness, a grinding fineness test must first be carried out for this purpose.

2. Pretreatment agent selection test

Gold leaching agent selected preprocessing is needed to test, usually without the need for the commonly used calcium peroxide, sodium hypochlorite, sodium peroxide, hydrogen peroxide, citric acid, and lead nitrate pretreatment agent pretreatment agent conventionally comparison object Is to determine if a pre-processing job is required.

Calcium peroxide, sodium hypochlorite and sodium peroxide are all very stable and widely used multi-functional inorganic peroxides, and have the characteristics of long-term oxygen release. In the leaching pulp, oxygen can be slowly released for a long time, which is beneficial to increase the leaching rate of gold. .

Hydrogen peroxide and citric acid provide sufficient oxygen during the leaching process, which is the main reagent for oxygen generation. The lead ion of lead nitrate (appropriate amount) can destroy the gold passivation film during cyanide leaching, accelerate the dissolution rate of gold and reduce The cyanidation time increases the leaching rate of gold.

3. Protection of alkali lime dosage test

In order to protect the stability of the sodium cyanide solution or the non-toxic immersion gold agent, the chemical loss of the gold leaching agent is reduced, and an appropriate amount of alkali must be added in the leaching to maintain the slurry with a certain alkalinity. The alkalinity is within a certain range. With the increase of alkali concentration, the gold leaching rate is constant, and the amount of gold leaching agent is correspondingly reduced. If the alkalinity is too high, the dissolution rate and leaching rate of gold decrease, so it is necessary to determine Suitable to protect the amount of alkali and the pH of the pulp. Tests and production usually use lime, which is widely sourced and inexpensive, as a leaching protection base. In order to determine its specific usage, it provides guidance for actual production.

4. Gold immersion agent dosage test

In the immersion gold process, the amount of gold leaching agent and gold leaching rate are proportional to a certain range, but when the amount of immersion gold agent is too high, not only the production cost is increased, but also the leaching rate of gold does not change much. To this end, on the basis of the grinding fineness test, in order to further reduce the amount of the immersion agent and the cost of the production agent, the amount of the immersion agent is tested to determine the appropriate amount.

5. Leaching time test

In order to achieve high leaching rate, the leaching time can be extended to fully dissolve the gold particles to extract the gold leaching rate. As the leaching time is extended, the gold leaching rate is gradually increased, and finally reaches a stable value. However, the leaching time is too long, and other impurities in the slurry are continuously dissolved and accumulated, which hinders the dissolution of gold. To determine the appropriate leaching time, a leaching time test was performed.

6. Slurry concentration test

At the time of leaching, the concentration of the slurry directly affects the leaching rate and leaching speed of gold. The higher the concentration, the higher the viscosity of the slurry, the lower the fluidity, and the lower the leaching rate of gold and the leaching rate of gold. When the concentration of the pulp is too low, the leaching speed and leaching rate of gold are high, but it will increase the equipment volume and equipment investment, and will also increase the amount of immersion agent and other chemicals proportionally, which will increase the production cost. In order to determine the appropriate leaching slurry concentration, a leaching slurry concentration test is performed.

7. Activated carbon pretreatment test

For the carbon leaching method, hard and wear-resistant activated carbon must be used to avoid the generation of fine-grained charcoal into the leaching residue during the agitation leaching process, resulting in loss of gold and reduced gold recovery. The test generally uses coconut shell activated carbon with a particle size ranging from 6 to 40 mesh. The activated carbon was pretreated under the following conditions: water: carbon = 5:1, stirred for 4 hours, and the stirring speed was 1700 rpm. The activated carbon after stirring for 4 hours was sieved with a 6 mesh and 16 mesh sieve. The fine-grained charcoal under the sieve is removed. That is, the carbon leaching and carbon adsorption tests are carried out using activated carbon having a particle size of 6 to 16 mesh.

8. Bottom carbon density test

The gold ore leaching test generally determines the use of 6-16 mesh coconut shell activated carbon to adsorb and recover the leached gold. After the gold-bearing carbon is produced, the mature activated carbon is used for analysis and electrolysis of the finished gold. The density of the bottom carbon directly affects the carbon adsorption rate. In order to select the appropriate bottom carbon density, the bottom carbon density test will be carried out.

9. Carbon adsorption time test

In order to determine the appropriate carbon leaching (carbon adsorption) time and reduce the wear of the gold-loaded carbon, a preliminary leaching and carbon leaching (carbon adsorption) time test is required after determining the total leaching time.

10. Carbon leaching process comprehensive conditions parallel test

In order to verify the stability of the carbon leaching test and the repeatability of the test results, it is necessary to carry out the parallel test of the whole process comprehensive conditions of the carbon leaching test, that is, after determining the above nine detailed condition tests, it is necessary to carry out the best conditions for the final test of each condition. Comprehensive verification test.

At this point, a complete carbon slurry leaching gold ore test ore dressing process test study is complete, of course, sometimes according to the actual production needs of the carbon leaching process tail water (lean liquid) return utilization test, carbon slag sedimentation rate Determination and the like.

Homeuse Tool Set