System and method for deeply purifying coal

Abstract

The invention relates to a system and a method for deeply purifying coal. The system is composed of a flotation column, a mixing tank, a circulating pump, a bubble generator, an oil storage barrel, a gasoline pump and an oil gas generator. The method comprises the following steps: adding kerosene or diesel oil into the oil gas generator and then heating and evaporating the kerosene or diesel oil,thereby generating kerosene or diesel oil steam; introducing the kerosene or diesel oil steam together with air into a floatation device, thereby generating oil bubbles; and promoting the wetting property of the bubbles under the condition of maintaining the floatation of a mineral main body, thereby achieving the purpose of promoting the floatability of the mineral. The problem of difficulty in flotation of low-rank coals can be solved, the rate of multipurpose utilization of the coal can be increased and the economic value can be promoted. The system and method provided by the invention aresuitable for deeply purifying the low-rank coals with low metamorphic grade, such as brown coal, long flame coal, non-caking coal, weakly caking coal, gas coal, and the like, can be used for greatly promoting the yield of clean coal and can be used for obviously reducing the dosage of the kerosene or diesel oil used as a collecting agent. The system has the advantages that the structure is simple, the operation is convenient, the floatation index of the low-rank coals is excellent and the dosage is small.

Description

technical field [0001] The present invention relates to a deep purification system and method for coal, especially a system and method for deep purification of coal using oil bubbles as a flotation carrier, which is suitable for lignite, long-flame coal, non-sticky coal, weakly sticky coal and gas Deep purification of low rank coal such as coal. Background technique [0002] In conventional flotation, kerosene or diesel oil is directly added into the coal slime water in a liquid state and dispersed under the action of stirring. Theoretically speaking, the thickness of the oil film on the surface of coal particles only needs to be one to two molecules thick, but due to the incompatibility of oil and water, The conventional direct drug delivery method cannot disperse the drug evenly in the pulp, resulting in too large oil droplets, so that the coal particles with a small particle size and a large number collide with each other and contact with the drug droplets with a large pa...

AI Technical Summary

Problems solved by technology

[0002] In conventional flotation, kerosene or diesel oil is directly added into the coal slime water in a liquid state and dispersed under the action of stirring. Theoretically speaking, the thickness of the oil film on the surface of coal particles only needs to be one to two molecules thick, but due to the incompatibility of oil and water, The conventional direct drug delivery method cannot disperse the drug evenly in the pulp, resulting in too large oil droplets, so that the coal particles with a small particle size and a large number collide with each other and contact with the drug droplets with a large particle size and a small number. Opportunities are reduced, leading to high oil consumption, and low-rank coals have low coal ranks, high oxygen-containing functional groups in coal, and poor surface wettability, which tends to be more hydrophilic. Particles are not easy to attach to the air bubbles and it is difficult or impossible to float. Therefore, it can only be compensated by increasing the dosage of chemicals (usually up to 50Kg / t-100Kg / t flotation feed). However, excessive chemicals are not only waste If the collector is added, it will also cause the collector to cover the fine mud on the surface of the coal particles while being adsorbed by the coal, resulting in the pollution of the fine mud, and it is difficult for the subsequent production process, such as sedimentation, filtration, pumping, etc. Eliminate side effects

For example, if a non-caking coal with a feed ash content of 30% is selected by conventional flotation, kerosene is directly added to the coal slime water in a liquid state. When the kerosene consumption is 80Kg / t dry coal slime, the obtained flotation concentrate The ash content of coal and tailing coal is 13% and 42% respectively, the yield of clean coal is 41%, the consumption of kerosene is large, and the flotation result is not ideal

In addition, most of the coal flotation reagents are petrochemical products or by-products, and the price is high, which makes flotation unfeasible from an economic point of view.

Images