▎ 摘　　要

NOVELTY - Production of calcium chloride dihydrate and graphene using chlor-alkali hydrochloric acid includes calcining massive limestone, crushing, digesting with water, pulverizing, and separating to obtain high-grade calcium hydroxide powder and low-grade calcium hydroxide powder; calcining high-grade calcium hydroxide powder to obtain activated calcium oxide to be used as catalyst, and growing graphene to obtain graphene-calcium oxide composite powder; and neutralizing with chlor-alkali hydrochloric acid composite powder to obtain mixture of graphene and calcium chloride solution, filtering to obtain graphene filter cake and primary filtrate, washing graphene filter cake with distilled water, collecting graphene washing liquid, drying washed graphene filter cake to obtain graphene powder, neutralizing primary filtrate with low-grade calcium hydroxide to adjust pH, settling, filtering to obtain secondary filtrate, evaporating and concentrating to obtain calcium chloride dihydrate. USE - The method is for production of calcium chloride dihydrate and graphene using chlor-alkali hydrochloric acid. ADVANTAGE - The method achieves simultaneous production of calcium chloride dihydrate and graphene, and expanded the industrial chain of chlor-alkali industry. DETAILED DESCRIPTION - Production of calcium chloride dihydrate and graphene using chlor-alkali hydrochloric acid comprises: (A) high-temperature calcining massive limestone to obtain massive quicklime, crushing, digesting with water, pulverizing, and separating to obtain high-grade calcium hydroxide powder with calcium hydroxide mass content of greater than or equal to 95% and low-grade calcium hydroxide powder with calcium hydroxide mass content of 65-90%; (B) calcining high-grade calcium hydroxide powder at high temperature to obtain activated calcium oxide to be used as catalyst, and growing graphene through chemical vapor deposition to obtain graphene-calcium oxide composite powder; (C) neutralizing with chlor-alkali hydrochloric acid composite powder to obtain mixture of graphene and calcium chloride solution, filtering to obtain graphene filter cake and primary filtrate, washing graphene filter cake with distilled water, collecting graphene washing liquid, drying washed graphene filter cake to obtain graphene powder, neutralizing primary filtrate with low-grade calcium hydroxide to adjust pH to 8-9, settling, filtering to obtain secondary filtrate, evaporating and concentrating to obtain calcium chloride dihydrate; and (D) neutralizing hydrogen chloride exhaust gas generated during chlor-alkali hydrochloric acid composite powder neutralization reaction, absorbing by graphene washing liquid until mass concentration of hydrogen chloride reaches 25-36%, and reusing repeatedly. An INDEPENDENT CLAIM is included for a calcium chloride dihydrate and graphene production system comprising quicklime preparing system, calcium hydroxide preparing system, graphene preparing system, calcium chloride dihydrate preparing system, and exhaust gas recycling system. The quicklime preparing system comprises limestone storage tank, first belt conveyor, limestone calcining device, second belt conveyor and quicklime storage tank. The calcium hydroxide preparing system comprises third belt conveyor, calcium hydroxide preparing device, first elevator and high-grade calcium hydroxide storage tank. The graphene preparing system comprises first screw conveyor, graphene growth system, first pipe chain conveyor, graphene-calcium oxide storage tank, second pipe chain conveyor, enamel reactor, first hydrochloric acid pump, hydrochloric acid storage tank, first filter press pump, first filter press, clean water pump, distilled water storage tank, second screw conveyor, flash dryer, packaging machin, and second hydrochloric acid pump. The calcium chloride dihydrate preparing system comprises third pipe chain conveyor, neutralizing tank, first calcium chloride conveying pump, settling tank, second filter press pump, second filter press, second calcium chloride conveying pump, calcium chloride solution storage tank, third calcium chloride conveying pump, evaporator, pellet mill, and calcium chloride dihydrate storage tank. The exhaust gas recycling system comprises third hydrochloric acid pump, graphene washing liquid storage tank, fourth hydrochloric acid pump, exhaust gas absorbing device, hydrochloric acid circulating pump, absorbing liquid storage tank, fifth hydrochloric acid pump, and acid-resistant draft fan.