Cyanide concentration determination method in cyanide leaching process of antimony-containing gold ore

Abstract

The invention relates to the technical field of ion concentration detection, in particular to a cyanide concentration determination method in the cyanide leaching process of antimony-containing gold ore, which comprises the following steps: step 1, taking cyanided ore pulp and filtering to obtain clear liquid 1; step 2, adding excessive solid Pb (NO3) 2 into the clear liquid 1 obtained in the step 1 step by step, and filtering to obtain clear liquid 2; step 3, adding excessive solid NaOH into the clear liquid 2 obtained in the step 2, and filtering to obtain clear liquid 3; and step 4, taking a certain amount of the clear liquid 3 obtained in the step 3, adding ammonia water into the clear liquid 3, then adding potassium iodide into the clear liquid 3, titrating with an AgNO3 standard liquid, and recording the consumption of the AgNO3 standard liquid to calculate the cyanide concentration in the ore pulp when a light yellow precipitate appears in the solution. The method has the beneficial effects that the excessive Pb (NO3) 2 is used for removing S < 2-> influencing titration in the ore pulp, and then the excessive NaOH is added for removing Pb < 2 + > influencing the KI indicator, so that the influence of impurity ions on cyanogen titration is eliminated, and the rapid real-time monitoring of the cyanogen concentration can be realized.

Description

technical field [0001] The invention relates to the technical field of ion concentration detection, in particular to a method for measuring the concentration of cyanide in the process of cyanide leaching of antimony-containing gold ore. Background technique [0002] Because cyanidation gold leaching has a series of advantages such as simple operation method, low operation cost and high degree of technology, cyanide leaching gold is still the most widely used in the existing gold leaching technology. [0003] In the process of cyanide leaching gold, gold dissolution and some impurity elements will consume cyanide. If the concentration of cyanide in the pulp is too low, the dissolution rate of gold in the cyanidation process will be too slow, and the time required for gold to reach a high leaching rate will be too long; if the concentration of cyanide in the pulp is too high, it will lead to excessive consumption of cyanide , the cost increases, and the waste residue wastewat...

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Problems solved by technology

The distillation method requires a long detection time, about 1-2 hours, and cannot achieve the purpose of rapid determination, so it is not suitable for process control analysis; both the silver nitrate method and the rhodanine method can quickly determine the concentration of free CN- within a few minutes , the basic principle is roughly the same, the difference is that the color of the solution at the end of the titration is different, the silver nitrate method shows milky yellow, and rhodanine shows light red

[0005] However, the silver nitrate method and the rhodanine method are only suitable for the rapid determination of free cyanide in the cyanidation process of oxidized ore with simple components. When the ore pulp contains other ion components that can react with silver ions or precipitate , it will have an impact on the test results, resulting in the inability to observe and judge the titration end point and the detection is inaccurate

[0006] In the process of cyanidation gold leaching of antimony-bearing gold ores, due to the antimonite (Sb 2 S 3 ) is prone to oxidative dissolution in the alkaline cyanidation process, thus producing a large amount of S 2- The ions enter the solution phase, and the Ag in the standard titration solution during the titration + will take precedence over S 2- The reaction produces a brownish-red precipitate, which consumes Ag + , which will result in the titration of consumed Ag + Too much, the measured cyanide concentration has a large deviation; moreover, the Ag produced in the titration process 2 The S precipitate is brownish red, whether it is the silver nitrate method or the rhodanine method, the color development of the subsequent titration end point is covered, and the titration end point cannot be observed

[0007] If adopting the method of precipitating sulfide ion with silver nitrate first, and then measuring the cyanide concentration after filtration, because excessive silver nitrate must be added earlier, the amount of subsequent dripping of silver nitrate titration solution will be reduced, resulting in low detection results. Moreover, a large amount of silver nitrate reagent will be consumed, and the detection cost will increase significantly.

[0008] In the existing cyanide concentration detection technology, there is no better solution to this phenomenon

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