Zinc electrolysis method for controlling Pb quality in electric zinc using Pb automatic analyzer

摘要

PURPOSE: To efficiently and stably produce the electrolytic zinc low in Pb by continuously monitoring the Pb concn. in a zinc electrolyte to predict the Pb grade of an electrolytic zinc slab and controlling the amt. of an additive to be added and so on. CONSTITUTION: An anode 2 consisting of lead electrode and a cathode 3 are dipped in a zinc electrolyte, power is supplied from an SCR 5 to bring about electrolysis, and an electrolytic zinc slab is deposited on the cathode 3. In this zinc electrolyzing method, the overflowing waste electrolyte is introduced into a circulating tank 6, a frsh electrolyte is replenished to make up for the deficiency, the mixture is transferred to a mixing tank 4 through a circulating pump 7, a lead absorptive additive such as strontium carbonate is added, and the admixture is returned to an electrolytic cell. In that case, the waste electrolyte is sampled in a lead analyzer 8, the Pb in the electrolyte is measured at least every 120min, and the amt. of additive to be added is controlled. A stripping voltammetry analyzer is used as the lead analyzer 8, and the Pb is preferably measured at 43-43 deg.C. An ultrapure zinc contg. =10ppm Pb is obtained in this way.