Mineral flotation is the use of differences in the physical and chemical properties of mineral and mineral impurities to achieve the sorting process. In order to enhance the sorting effect, various flotation agents are added to the flotation, and the flotation agent is a general term for various chemical agents used for realizing or promoting flotation. The role of the flotation agent is mainly to improve the hydrophobicity of the mineral surface and the firmness of the mineral adhesion on the bubble; promote the formation of a large number of bubbles in the slurry, prevent the bubble from merging and improve the stability of the foam, so that the mineral selectively adheres to the bubble and rises Adjust the surface properties of minerals and mineral impurities to increase the flotation rate and selectivity of minerals. Second, the classification of flotation agents Classified by action 1. Flotation agents can be divided into the following categories according to their functions: (1) Collector The collector refers to a flotation agent added to the coal slurry to increase the hydrophobicity of the surface of the coal particles, making it easy and firmly adhered to the bubbles. The most commonly used collectors in flotation are non-polar hydrocarbon compounds such as kerosene, light diesel oil and the like. (2) Foaming agent The foaming agent refers to a flotation agent used to control the bubble size and maintain the stability of the bubble during the flotation process. Among these flotation agents are various organic surface active substances such as fatty alcohols. (3) Conditioner Adjusting agent refers to a flotation agent that adjusts the properties of coal slurry and mineral surface to improve the efficiency of a certain flotation agent or eliminate negative effects. The adjusting agent for coal preparation mainly includes: Medium pH adjuster—Flotation agent that adjusts the pH of coal slurry to change the electrical properties of coal particles and mineral impurities to improve the selectivity of the flotation process. Among these types of flotation agents are lime, sulfuric acid and the like. Inhibitor--Flotation agent used in flotation process to control the harmful behavior of mineral impurities on sorting, reduce the hydrophobicity of a certain mineral surface, make it difficult to float, and improve the separation of coal and mineral impurities. Belong to this flotation agents are sodium metasilicate, sodium silicate, sodium hexametaphosphate and starch. (4) Other Others are emulsifiers for increasing the dispersion of non-polar oils in coal slurry. It must be pointed out that the above categories of flotation agents are distinguished by their basic role. In fact, due to the influence of the composition of the structure, it usually does not only play a role, but also has other effects. Certain flotation agents fall into this category under certain conditions, and may change to another category after conditions change. 2, classified by molecular structure Flotation agents can be classified into the following categories according to their molecular structure: (1) Polar flotation agent Such flotation agent molecules on the whole is electrically neutral, but has two electrodes, like the bar magnet having two poles, as they can attract polar water molecules, hydrophilic, soluble in In water, such as various acids, alkalis, salts. (2) Non-polar flotation agent The molecular positive charge of this type of flotation agent and the electric center of gravity of the negative charge are coincident. They do not dissociate in water, and are basically unable to attract polar water molecules. The hydration is small and hydrophobic. They are suspended in water in the form of small oil droplets, such as hydrocarbons (oils). (3) complex polar flotation agent (also known as heteropolar flotation agent) The molecules of this type of flotation agent consist of two parts, the polar part (often called the polar group) and the non-polar part (often called the non-polar group). The polar group is hydrophilic and the non-polar group is hydrophobic. Figure 1 is a schematic illustration of the interaction of different flotation agent molecules with polar water molecules. In the figure, (a) is a hydrophobic non-polar molecule; (b) is a hydrophilic polar molecule; (c) is a heteropolar molecule having one end hydrophilic and one end hydrophobic. Figure 1 Schematic diagram of the interaction between flotation agent molecules and polar water molecules
Hardware Metals,Metal Hinges,Metal Knobs,Metal Drawer Handles CHANGZHOU LVSONG INTERNATIONAL TRADING CO.LTD , https://www.yuanhangsupply.com
The role and classification of flotation agents
First, the role of flotation agent