Galena three acidic ferric chloride leaching of a saturated saline, and generating elemental sulfur dichloride, lead, lead dichloride salt was dissolved in hot water and filtered while hot, cooling the filtrate to obtain crystals of lead dichloride; two then lead chloride molten salt electrolysis to obtain the metal lead and chlorine; chlorine oxide to ferric chloride, ferric chloride to make it into, recycling. The main reactions are as follows: The electrolyte consists of 25% LiCl, 32% KCl and 45% PbCl 2 . When electrolysis, a current of 3000 A is applied, and the electrolysis temperature is 450 ° C. The liquid metal lead produced by electrolysis is placed in a mold placed in a vacuum chamber by a siphon, and precipitated. C1 2 is led to the bottom of the chlorination column through a fiber reinforced plastic tube, and FeCl 2 is oxidized to FeCl 3 for recycling. This cell produces 226.8 kg of lead metal per day and consumes 1168 kW·h of lead per ton. In this process, the production cost per ton of lead (including raw materials such as salt, hydrochloric acid, chlorine, and lime other than ore, labor, maintenance, taxes, insurance, depreciation, etc.) is $108, which is similar to the fire method. Trench Cutting Re-mixing Deep Wall Machine Trench Cutting Re-Mixing Deep Wall Machine,Wall Construction Equipment,Underground Wall Forming Machine,High-Speed Wall Forming Machine Xuzhou Jingan Heavy Industry Manufacture Co.,Ltd. , https://www.jinganmachine.com
Leaching: PbS+2FeC1 3 ==== PbCl 2 +2FeCl 2 +S o
Electrolysis: Negative electrode: PbCl 2 +2e ==== Pb ↓ +2Cl -
Positive electrode: 2Cl - -2e ==== Cl 2
Regeneration: 2FeC1 2 +Cl 2 ==== 2FeC1 3
MM Wong reported in 1980 the details of the galena-lead ferric chloride leaching-lead dichloride-salt electrolysis expansion test conducted by the Renault Metallurgical Research Center of the US Bureau of Mines [1] . Concentrate 50kg, intermittent operation, the leaching tank is a steel drum with a polyvinyl chloride lining and a titanium heating tube, the volume is 1.5m 3 . The leachate contained 73 g/L of FeC1 3 , 254 g/L of NaCl, and pH=3. The temperature is about 100 ° C, the reaction is 30 min, the lead leaching rate is 98%, the copper and silver leaching rate is 80%, and the zinc leaching rate is about 70%.
The inner wall of the electrolytic cell is made of quartz brick with a size of 865mm x 635 mm x 457mm, the cathode is a graphite plate, and the anode is a graphite rod. The following figure is a schematic view of the electrolytic cell. 
The advantages of this process are: the realization of the wet method lead smelting, the basic solution to the environmental pollution and lead poisoning problems in the lead smelting method; the recovery of most of the associated metals and sulfur; the production scale can be large or small.
The disadvantages of this process are: the use of chloride system leaching and electrolysis, high requirements for equipment materials, PbCl 2 is easy to crystallize, and it is difficult to transport slurry, filtration, etc.; electrolysis temperature is 450 ° C, chlorine gas is generated, there are unsafe factors; The trough structure is more complicated; gold in the ore cannot be recovered.
references:
1 MM Wong, Paper Presented at the 109th AIME Annual Meeting at Lasvegas, Nevada, Feb. 24-28, 1980