The ore contains harmful elements such as arsenic, carbon and antimony. Arsenic and antimony are easy to pollute the surface of gold, and even form a film on the surface of gold minerals; The carbon content is 3.88%, which is easy to adsorb gold. The particle size of gold is very fine and exists as submicroscopic gold. It is wrapped by pyrite and arsenopyrite, and the particles of pyrite and arsenopyrite are fine, which brings great difficulties to the flotation cyanidation process. Several constants are given below
Specify the sorting index of the sorting process.
1. Full slime cyanidation of raw ore: gold leaching rate 0~8%;
2. Flotation tailings cyanidation: when the ore is 1g/t, the leaching rate is 0;
3. Flotation - cyanidation of gold concentrate: the concentrate grade obtained by flotation is 59g/t, and the leaching rates of direct cyanidation or regrinding cyanidation are 1.45% and 3.33% respectively.
It can be seen that the conventional flotation and cyanidation process is not suitable for this ore. In order to obtain a higher gold recovery rate, we must strengthen the flotation operation to obtain the best flotation gold recovery rate, and then treat the gold concentrate. To this end, the following measures have been taken in flotation operation:
1. Sufficient fine grinding. Due to the fine particle size of gold and its carrier minerals, in order to dissociate it from gangue minerals, it should be ground as fine as possible under the conditions allowed by industrial production.
2. Add appropriate adjusting agent in grinding operation. For example, the flotation of sodium carbonate and pyrite is completed in weakly alkaline pulp, which is weakly acidic. At the same time, under intense stirring conditions, arsenopyrite and pyrite can be oxidized and the influence of some impurity ions on pyrite flotation can be eliminated. Thus, the floatability of gold and its carrier minerals is improved.
3. Add an appropriate amount of activators, such as copper sulfate, lead nitrate, etc., and stir them fully for a long time to activate the surface of minerals. Make gold and its carrier minerals pyrite and arsenopyrite float fully.
4. Make full use of the good selectivity and collectability of butyl dumpling black medicine and isoamyl xanthate and the synergistic effect of mixed drugs. The double optimal flotation indexes of high grade and high recovery string were obtained.
Taking the above measures, a good flotation index with gold grade of 63.38g/t and recovery of 88.84% was obtained. The tailings grade is reduced to 0.60g/t.
Test conditions: -0.045mm accounts for 90%. The dosage of butyl is 30g/t, the dosage of sodium carbonate is 3000g/t, the dosage of Isoamyl xanthate is 60g/t, the dosage of copper sulfate is 100g/t, and the dosage of 2# oil is 50g / t.
