Gold ore | Fine-grained gold ore flotation beneficiation

my country's gold mines have many associated ores and many poor ores. Although the reserves of gold ore resources are large, a considerable number of mines have a low degree of development and utilization.

The level of flotation technology is backward, and the recovery rate of gold flotation is generally 70% to 80%, and some are even only about 20%. Due to technical bottlenecks, it is difficult to achieve efficient recovery of fine-grained complex refractory gold ore.

Features of fine-grained complex refractory gold ore:

1. Some gold minerals are embedded with extremely fine particle size, 55% of which is less than 0.01mm, and the minimum visible particle size is 530nm, which makes it difficult for gold minerals and gold-carrying minerals to dissociate and easily lost in tailings.

2. The thickness is uneven, and some gold-loaded pyrite with relatively coarse particle size has many cracks, and it is easy to be too crushed during fine grinding, resulting in the loss of gold.

3. The raw ore contains a lot of layered silicate minerals such as muscovite and biotite, carbonaceous materials and some clay minerals, which have an adverse effect on the flotation of gold.

4. The nature of the raw ore fluctuates greatly and adversely affects the flotation.

5. A large amount of polymer flocculant is added to the dehydration of the dense system, which causes the backwater to have an adverse effect on the flotation.

In response to these technical difficulties, five technical measures have been taken.

1.Adopt high-efficiency dissociation technology. In view of the ultra-microscopic state of gold in this gold deposit, and at the same time, the main carrier minerals of gold, pyrite, arsenopyrite or other minerals are mostly unevenly distributed in thickness and size. The gangue minerals obtained efficient and reasonable dissociation.

2. Adopt the new technology of sub-flow and sub-speed flotation. Due to the differences in the particle size of (carrying) gold minerals and the floatability of different minerals, a semi-closed and semi-open process is adopted, with split flow, sub-speed, and combined with staged dissociation to expand (carrying) gold minerals and the floatability of gangue. difference, so that gold can be recovered efficiently.

3. Use strong collecting agents, such as BK903G, BK302A or MA, to increase the recovery of fine-grained gold and gold-loaded minerals.

4. Reduce or cancel the amount of water glass, accelerate the settlement of tailings, and greatly reduce the amount of polymer flocculants used, thereby reducing the adverse effect of backwater on flotation operations.

5. According to the nature of the ore and the requirements of the new process, adding chemicals in stages will play a positive role in improving and stabilizing the gold recovery rate.