Production method for extracting lignite wax from brown coal

Abstract

The invention relates to a production method for extracting lignite wax from brown coal. The production technology comprises the steps of (a) multi-stage countercurrent pulse extraction; (b) negative-pressure countercurrent film evaporation; and (c) negative-pressure distillation concentration, wherein an extraction solvent in the step (a) is mixed solution of methanol to industrial n-hexane, of which the solvent mass ratio is (0.5-0.8):1; and the mass ratio of the extraction solvent to the brown coal is (1.5-1.8):1. By adopting the production method, the yield of the lignite wax is greatly improved; large-scale and industrial production is achieved; the problems of large solvent input and low extraction yield in industrial production of the lignite wax are solved; and the production method is free of environmental pollution, and low in production cost, is an innovative technology of extracting the lignite wax from the brown coal, and has great economic benefit and social benefit.

Description

technical field [0001] The invention relates to a preparation method of chemical materials, in particular to a production method of extracting montan wax from lignite. Background technique [0002] Lignite, also known as firewood coal, is the mineral coal with the lowest degree of coalification, a brown-black, dull low-rank coal between peat and bituminous coal. Montan wax is a rare mineral. Germany first began to extract wax from lignite in 1897, so it is also called Montan Wax abroad. It is a mineral wax containing waxes, resins and bitumen. A mixture containing waxes, resins and bitumen extracted from waxy coals such as lignite or certain peats by solvents such as benzene and gasoline. The properties of montan wax mainly depend on the raw material, the solvent used and the extraction conditions. With the increase of bitumen content, its color changes from brown to black. [0003] At present, domestic montan wax manufacturers in Xundian, Eshan, Jilin, and Wudan, Inner ...

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Problems solved by technology

[0003] At present, domestic montan wax manufacturers in Xundian, Eshan, Jilin, and Wudan, Inner Mongolia mostly use benzene and toluene as extraction solvents to extract montan wax from lignite, but benzene solvents pollute the environment and endanger human body Healthy, there are still benzene solvent residues in the extracted montan wax; Also, CN101906320A discloses a production method of high-purity montan wax, which includes solvent extraction, and is characterized in that during extraction, adding a solvent until the lignite is not crossed, so The solvent is composed of the following components in mass ratio: isopropanol 20-100%, alcohols or hydrocarbons or water 0-80%, and the alcohols are one or more of methanol, ethanol, tert-butanol Described hydrocarbon is one or more in sherwood oil, No. 6 solvent, normal hexane, hexanaphthene, but the deficiency that these several kinds of solvents extract montan wax is that energy consumption is big, production cost is high; CN101029255A discloses a A kind of montan wax green extraction solvent and production process, using a mixed solvent of cyclohexane and alcohols; crushing and screening the lignite, putting the lignite coal particles into the extraction tank, according to the solid-to-liquid volume ratio of 1:1 to 1: The ratio of 4 is put into the mixed solvent for extraction, and the extracted solution is flashed to recover the solvent; the residual mixed solvent is evaporated through the cooking system to obtain the crude montan wax; the evaporated mixed solvent steam is condensed by a heat exchanger, and then Carry out oil-water separation, send the cyclohexane in the upper layer to the solvent storage tank; separate the tert-butanol and water in the lower liquid by rectification, and import the separated tert-butanol into the solvent storage tank; detect the cyclohexane or The content of tert-butanol, add pure cyclohexane and pure alcohol solvents, and make the ratio of the two mixed solvents meet the requirements, and then continue to use

This invention process is complicated, and the amount of used solvent is big

[0004] There are some deficiencies in the currently developed process of producing montan wax from lignite, so developing a production method with low production cost and little pollution is a work of great significance for the development and utilization of montan wax, a scarce mineral resource.

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