High-efficiency separation method of caustic lye

Abstract

The invention discloses a high-efficiency separation method for caustic lye, which comprises the following steps: A. pretreating the quicklime, crushing and screening to remove large stones and dregs to obtain quicklime powder; B. elevating the quicklime powder into the caustic The causticization reaction is carried out under the action of mechanical stirring in the chemical tank; C. After the causticization reaction is completed, the material is gradually fed into the centrifugal separation equipment under stirring, and separated at a low speed of 18-25m / s for 15-20min to promote the formation of the filter screen interface Material filter cake, stop feeding after the thickness of the filter cake reaches the specified value, and then separate at a high speed of 50-60m / s for 20-30min; D. The moisture content of lime residue after high-speed separation is controlled below 5%, reaching Landfill after safe landfill conditions. The invention solves the technical problems in the industry and eliminates the hidden dangers to the environment and personal safety. The separated lime slag can be calcined to produce lime and produce CO2 gas for industrial production, such as a gas source for sodium phenate decomposition. The invention is a practical technology for recycling resources and realizing clean production.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to an efficient separation method for caustic lye in industrial naphthalene production. Background technique [0002] In the coal tar deep processing industry in the field of coal chemistry, in order to achieve the maximum comprehensive profit, the mixed fraction is first dephenolized with lye sodium hydroxide and then deep processed to extract primary products such as phenol oil, naphthalene oil and washing oil fraction. After dephenolization, the phenol sodium salt must reduce the phenol, and the raffinate is sodium carbonate (Na 2 CO 3 ) and sodium bicarbonate (NaHCO 3 ), in order to realize the optimization of industrial production cost, the raffinate is converted into sodium hydroxide (NaOH) by using quicklime (CaO) as the raw material for dephenolization, so as to realize the recycling of raw materials, which is equivalent to using only cheap and easy...

AI Technical Summary

Problems solved by technology

The more mature process is to use a vacuum filter to filter and clean with water to recover as much sodium hydroxide (NaOH) as possible, which leads to low concentration of sodium hydroxide (NaOH) lye, and supplements caustic soda (solid hydrogen) Sodium oxide, the content is about 95%), and the method of increasing the concentration produces the inexhaustible total lye and discharges it, which not only causes waste, but also pollutes the environment, and forms a pressure on the wastewater treatment process

However, the evaporative dehydration method is used to increase the concentration of sodium hydroxide (NaOH) lye, and the moisture content of lime slag (mainly calcium carbonate CaCO3) is as high as 40-50%, which is not convenient for transportation or storage, and landfills pollute the environment

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