electrolytic lead refining 铅电解精炼

Bett lead-refining 贝特炼铅法

continuous lead refining 铅的连续精炼

lead-refining furnace operator 铅精炼炉操作员

fluosilicate lead refining process 氟硅酸盐炼铅法

fire refining of crude lead 粗铅火法精炼

lead electro-refining 铅电解精炼

kettle for refining lead 铅精炼锅

lead bullion fire refining 粗铅火法精炼