Gold ore flotation process is a kind of gold extraction process that was applied earlier and is still in use today. A 200tpd gold ore dressing plant entrusted Xinhai to help transform its flotation process due to the poor effect. This article takes this concentrator as an example to introduce the flotation process and beneficiation equipment of 200tpd flotation plant.
The type of ore process is fine-grained disseminated refractory gold ore containing arsenic, antimony and organic carbon. The idea of the process flow is to first use the flotation process to enrich gold and get gold concentrate, and then process the gold concentrate in order to reduce the investment and cost of development and utilization of the ore. The flotation process consists of one roughing, two concentrating, and two sweeping processes. But the flotation effect is poor because the surface of arsenic and antimony minerals is easily oxidized and adsorbs a large amount of flotation reagents.
The technological process of the gold ore is to crush and grind the ore first, and the dissociated minerals enter the flotation machine for dosing flotation. The flotation of gold minerals generally adopts a one-stage grinding-flotation process. For ores with uneven particle size, a staged grinding-flotation process can be used. In China, a stage of grinding-flotation-flotation process is generally adopted to achieve the enrichment of useful minerals.
1. Crushing
This stage is mainly to initially crush the gold ore, realize the effective dissociation of the material structure of the gold ore, and reduce the difficulty of subsequent grinding. Generally, small size and high-efficiency jaw crushers, impact crushers and cone crushers are used.
2. Grinding
Generally speaking, for gold encapsulated in sulfide minerals, only the sulfide ore monomer needs to be dissociated, but the grinding fineness of gold connected with gangue needs to reach the gold monomer dissociate. At the same time, the grinding fineness of a certain mineral is determined by experiments.
3. Flotation
The principle of gold ore flotation is: for flotation of minerals with high density and coarse particle size, thicker pulp is often used; on the contrary, when flotation of small density, fine particle size and slime, thinner pulp is used, and thicker pulp is used for coarse flotation, which can ensure a higher recovery rate. A thinner concentration is used for selection, which is conducive to improving the quality of the concentrate.
The 200tpd gold beneficiation equipment mainly includes jaw crusher, cone crusher, linear vibrating screen, wet ball mill, hydrocyclone and flotation machine. In view of the existing problems in the original production and combined with the actual production, Xinhai has carried out technical transformation on the process flow, and changed the cyclone tail throwing of the original gold mine flotation equipment to stage grindin-flotation, flotation throwing tail, so that the process is smooth and easy to use. In addition, the number of equipment and flotation reagent system in some processes were improved, and the final indicators were excellent.
The specific indicators before and after the transformation of the 200tpd gold ore dressing plant are compared as follows:
| product name | gold concentrate grade/（g/t） | gold recovery rate/% | |
| before remodeling | gold concentrate | 33.35 | 81.80 |
| tailings | 0.68 | 9.38 | |
| raw ore | 3.32 | 100 | |
| after transformation | gold concentrate | 34.38 | 90.62 |
| tailings | 0.34 | 19.20 | |
| raw ore | 3.30 | 100 |
The original gold ore flotation process is changed to a stage grinding and flotation process, which is easier to operate, and can achieve early and fast recovery of useful minerals in ores with high impurity content; adjust the structure of the flotation machine to improve the separation environment, which also improves the mineralization effect of the flotation pulp and ensure the stability of the index and the smooth flow of the process.
