A method for producing desulfurizer from calcium carbide slag

Abstract

The invention provides a method for producing a desulfurizing agent from carbide slag, which is classified as a dry process and a wet process according to the source of carbide slag; the carbide slag produced by dry acetylene production serves as raw material of the dry process; carbide slag slurry produced by wet acetylene production serves as raw material of the wet process; the dry process comprises the following steps of: 1) cyclone separation: removing heavy foreign matters from the carbide slag and carbide slag particles with fineness larger than 4mm; 2) raised dust filtration and separation at negative pressure: intercepting carbide slag particles with fineness larger than 0.04mm in a solid state at one time, and reducing the water content to less than 5%; 3) drying: controlling the water content to be between 1% and 3% to obtain dry powder of the desulfurizing agent; and (4) pulping: adding water accounting for 15%-30% of the final solid content and stirring evenly to obtain a liquid desulfurizer. The wet process comprises the following steps of: 1) sedimentation of washing sand: primarily removing large foreign matters and silicon iron particles from the carbide slag slurry; 2) selective filtration: removing solid particles with fineness larger than 0.04mm through controlling the thickness of a filter cake; 3) filtration and concentration: controlling solid content to be between 15% and 30% to obtain liquid desulfurizing agent; and 4) dewatering and drying: finally controlling the water content to be between 1% and 3% to obtain the desulfurizing agent.

Description

technical field [0001] The invention belongs to the recycling technology of waste slag in the production of acetylene by calcium carbide method, in particular to a method for producing desulfurizer by using calcium carbide slag. Background technique [0002] The industrial waste calcium carbide slag produced by the calcium carbide method to produce acetylene has a calcium-based content (calcium hydroxide) of 80-85%, which can replace calcium carbonate as a desulfurizer in the desulfurization system of a power plant; however, the composition of solid particles in calcium carbide slag is very complicated. In addition to calcium hydroxide and calcium oxide, it also contains various solid particle impurities such as carbon slag and ferrosilicon. Solid particles larger than 0.04 mm will cause wear and blockage of the pipeline of the desulfurization system of the power plant and the circulation system of the desulfurizer. Therefore, carbide slag must remove particles larger than ...

AI Technical Summary

Problems solved by technology

The production effect is also unsatisfactory. Apart from the high energy consumption and high cost of the "grinding" method, all impurities in the calcium carbide slag except calcium hydroxide are mixed into the desulfurizer and enter the desulfurization system; In other words, the amount of this desulfurizing agent will increase, and more importantly, the impurity in the desulfurizing agent will not be controlled, which will lead to impurities entering into the desulfurizing gypsum, affecting the color and purity of desulfurizing gypsum and even affecting the reuse of desulfurizing gypsum