As an efficient mineral processing technology, gold flotation technology plays an important role in modern gold extraction. It separates gold minerals from complex ores through physical and chemical methods to recover gold. With the increasing complexity and depletion of gold resources, flotation technology has become one of the most commonly used methods in gold extraction due to its high efficiency and flexibility. This article will comprehensively explore the principles and processes of gold flotation technology, aiming to provide a systematic reference for relevant practitioners and researchers.
Basic principles of gold flotation process
During the gold flotation process, the surface hydrophobicity of gold minerals and gangue minerals is selectively changed by adding appropriate flotation reagents. After the pulp is conditioned, the bubbles in the pulp interact with the hydrophobic gold mineral particles, causing them to adhere to the bubbles and float to the surface of the pulp, forming an enriched foam layer. Finally, by scraping off the foam product, the gold minerals and gangue minerals are separated, thereby improving the gold recovery rate. The flotation process mainly includes the following key links: pulp conditioning, bubble generation, mineral attachment, and scraping off the foam product.
Main process of gold flotation
1. Crushing
Crushing is the first step in gold beneficiation, and its purpose is to crush the primary ore to a particle size suitable for grinding. Usually a multi-stage crushing process is used, such as jaw crusher for coarse crushing, cone crusher for medium and fine crushing. The particle size of the crushed ore is generally controlled at about 10-20 mm for subsequent grinding operations.
2. Grinding
Grinding is to further grind the crushed ore to fully expose the gold minerals, thereby improving the flotation efficiency. Grinding equipment usually uses ball mills or rod mills, and the grinding fineness is generally required to reach -0.074 mm, accounting for 70%-80%. The grinding concentration and time must be strictly controlled during the grinding process to avoid over-grinding or under-grinding.
3. Flotation
Flotation is the core link of gold beneficiation. First, the ground slurry is slurried to a suitable concentration (usually 30%-40%), and then flotation agents such as collectors, frothers and regulators are added. Through stirring and aeration, the gold minerals in the slurry adhere to the bubbles to form a foam layer, which is then scraped out as concentrate. The flotation process is usually divided into three stages: roughing, concentrating and scavenging, to improve the recovery rate and grade of gold.
4. Concentration
The concentrate after flotation contains a lot of water and needs to be dehydrated by concentrating equipment (such as a thickener). The concentration process uses the principle of gravity sedimentation to settle the concentrate particles, and the upper clarified liquid is returned to the mineral processing process for recycling. The water content of the concentrated concentrate can generally be reduced to 40%-50%.
5. Filtration
The concentrated concentrate still contains a certain amount of water and needs to be further dehydrated by filtering equipment (such as a vacuum filter or filter press). The water content of the filtered concentrate can be reduced to 10%-15%, which is convenient for subsequent smelting or storage.
As above motioned, the gold flotation process can effectively improve the gold recovery rate and realize the efficient utilization of ore resources. With the continuous development of mineral processing technology, the application of new flotation equipment and reagents has further optimized the flotation effect and improved the economic benefits of mineral processing. In the future, with the improvement of environmental protection requirements and the development of low-grade complex gold resources, the gold flotation process will develop in a more energy-saving, efficient and green direction, providing technical support for the sustainable utilization of gold resources.
Tags:Gold Flotation
From:Xinhai Mining Machinery Company
