Recently, affected by the expectation of new tariff policies, market concerns about inflation and trade frictions have intensified. As a traditional safe-haven asset, gold has once again become the focus of capital pursuit, and its price has continuously refreshed historical highs. The continued rise in gold prices has driven the exploration and mining boom of gold mines around the world, especially in Africa, South America and parts of Asia. At the same time, the effective beneficiation and recovery technology of gold ore has become a key link for gold mining companies to improve their economic benefits. This article will give you an in-depth analysis of the types of gold ore and the current mainstream gold beneficiation technology and methods.
Main types of gold ore
Gold ore can be divided into the following categories according to its geological origin, mineral composition and occurrence state:
Quartz vein type gold ore
Gold is mainly found in quartz veins in the form of natural gold, often coexisting with pyrite. The particle size distribution of gold is wide, ranging from microscopic gold to coarse gold. This type of ore is generally of high grade and is the focus of current gold resource development.
Broken zone altered rock type gold ore
Gold is found in altered rocks affected by fractures and hydrothermal action. The ore structure is complex and is often accompanied by sulfides such as pyrite and chalcopyrite. Gold is closely combined with gangue minerals and is mostly embedded in fine particles, making beneficiation relatively difficult.
Volcanic rock type gold ore
Originated in volcanic rocks and subvolcanic rocks, it contains a variety of metal minerals, such as sphalerite and galena. The wall rock has rich alteration types, uneven ore grades, and often contains complex mineral components that interfere with beneficiation.
Placer gold ore
It is a secondary deposit formed by weathering, transportation and sedimentation. Gold mainly exists in loose gravel such as rivers and beaches in the form of coarse or flaky natural gold. Recovery is relatively easy, but the resource distribution is scattered and the grade is unstable.
Common beneficiation methods for gold ore – flotation method
Flotation method: Applicable to gold ores with complex metal coexistence
Flotation is to adjust the reagent system to make the surface of gold particles hydrophobic and attach to bubbles to achieve separation. It is applicable to sulfide gold ores or complex ores with gold and multiple metals coexisting.
1. Conventional flotation
Add collectors such as yellow medicine and black medicine to the slurry, adjust the pH value, make the gold particles float on the bubbles, and achieve concentrate separation.
Applicable ores: quartz vein type, broken zone altered rock type gold ores containing fine or micro-fine gold minerals.
2. Priority flotation
For gold and multiple metal coexisting ores, first recover a certain target mineral, and then separate other components to improve recovery efficiency and product grade.
Typical applications: gold-copper, gold-antimony, gold-lead-zinc polymetallic ores.
3. Mixed flotation
First float out all valuable minerals to form a mixed concentrate, and then reselect. Suitable for coexisting mineral groups with little difference in floatability.
Advantages: Simplified process, strong adaptability, suitable for preliminary enrichment process.
4. Equifloatable flotation
Float minerals with similar floatability and then separate them step by step.
Suitable for: polymetallic gold mines with large differences in floatability.
5. Branched series flotation
Multiple flotation processes are connected in parallel to improve flotation efficiency through the return of middlings or re-selection of concentrates.
Advantages: Good effect in dealing with the problems of wide distribution of ore particle size and uneven particle size.
There are various methods for beneficiation of gold ore, and different types of ores need to be equipped with targeted process flows. Whether it is traditional re-selection, flotation, cyanidation, or emerging biological gold extraction and non-cyanidation technology, it is necessary to conduct sufficient beneficiation tests and process design based on the actual ore properties.
Henan Kaiyun Intelligent Equipment Co., Ltd. has been deeply involved in the field of gold beneficiation for many years and has rich field experience and technical reserves. We can tailor the optimal gold extraction solution according to the characteristics of the customer’s ore to help achieve the goal of efficient, green and high recovery rate gold extraction.