The Basic Reserch Of Wasted Hydrochloric Acid Electrolysis And Waste Recycling

Hydrochloric acid is waste in inorganic chemical, organic synthesis, steelmetallurgical and other industry produces in the process of production of lowconcentration, with impurity, recycling low levels of pollutants. If wastedhydrochloric acid not be handled properly, which not only can cause the waste ofresources, but also can cause environment pollution. At present, waste recyclingand reuse of hydrochloric acid alternative water dissolved the salt, reducing theamount of the water. At the same time, electrolysis of chlorine gas can beproduced to use in chemical industry production, it is used in the chlor-alkailindustry, because of the advantage in this method. However, it consumes morepower in the recycling of waste hydrochloric acid. According to economicefficiency and environment, the energy reduction of the power in wastehydrochloric acid electrolysis process become the core problem. The slot voltageis the premise of reducing energy consumption in the electrolysis processthrough the slot voltage component relationship, therefore, in the process of apotential electrolysis minimization, mixed solution resistance and the reductionof the membrane resistance are important factor of minimizing the energyconsumption.In order to solve the waste hydrochloric acid in the process of the problemof energy consumption electrolysis, this study focus on reducing potential, mixedsolution resistance and the reduction of the membrane resistance from threeaspects, looking for energy consumption minimization.（1）Through the dynamic potential polarization measurement technology,polarization curves of titanium alloy, graphite, stainless steel and copper indifferent electrolyte concentration, different temperature and different currentdensity are measured, and the results show that electrolyte concentration is7%with HCl and NaCl mixed, electrolysis temperature is70℃and current density is0.2A/cm~2. Meanwhile, the electrolysis anode material is determined as titaniumalloy, and the cathode material as stainless steel. Therefore, a new way of thinking is provided for CPE enterprises and other similar enterprises based onchlor-alkali industry to improve economic returns to realize recycling wastehydrochloric acid by electrolysis.（2）According to studying, the most important factor of the cell voltage isthe current density. The optimal technology level: current density0.2a/cm~2,electrolysis temperature50℃, electrolyte concentration is7%HCl and NaClmixed solution. Verification experiment conclude that the current efficiency is95.11%, cell voltage is4.1V.（3）For pure NaCl in solution, the solution of electrical conductivity isincreased with temperature. As for as pure HCl solution is concerned, with therise of temperature conductivity is enlarged. For NaCl and HCl mixed solution ofthe conductivity is increased with the rise of temperature, solution concentration.However, mixture of electrical conductivity is not simply the superposition oftwo kind of solution.（4）Nylon, asbestos, polypropylene diaphragm are the permeabilitydiaphragm, rely mainly on the electrolyte solution of anion and cation migrationconducted current. Generally, the diaphragm with good function of aqueoussolution has small resistance of movement to the soak the anion and cation,therefore, the resistance value is lower. According to the experimentaldetermination, the paper will tell, the asbestos membrane resistance minimum isthe ideal of the membrane material choice, however, because existence ofpollution, with asbestos from corrosion, it is not durable, so we need to considerother membrane materials.