Lost Wax Castings,Heat Treatment Basket,Carbon Steel Casting,Stainless Steel Castings Dongying Wanlong Mechanical Mould Co,.Ltd , https://www.wlcasting.com
1. Common lead oxide minerals
The lead-lead PbCO 3 , containing 77.6% of Pb, is the most important lead oxide mineral, and is generally floated with xanthate after vulcanization. The white lead ore is easily vulcanized by sodium sulfide, and the most suitable pH for vulcanization is 9.5. If the amount of sodium sulfide is large during vulcanization, the sodium hydrogen sulfide can be used as a vulcanizing agent when the pH is too high. White lead ore is easily floated by fatty acids. However, it is not easy to separate from the gangue.
Lead bismuth PbSO 4 , containing Pb 68.3%, is similar in floatability to leucite, but it is longer than leucox and sodium sulphide is more than leuco. The optimum pH of lead bismuth vulcanization is 7-9. Because of the large solubility of lead bismuth, the collector is not easy to fix on the surface, but when the pH is 9.5~11, when a large amount of collector exists, a small amount of phosphorus is added. Sodium phosphate, lead bismuth can be partially floating.
PbMoO 4 with color molybdenum lead ore, containing 55.8% lead, similar in floatability to white lead ore. However, the effect of vulcanization and xanthate decreases with increasing temperature.
2. Lead oxide flotation method
There are two types of methods: flotation after flotation and direct flotation.
(1) After the vulcanization, the yellow medicine flotation method is used. This is the most common method, and it is worth noting the way this sodium sulfide is added. The concentration of sodium sulfide will cause the pH of the pulp to be too high, so that the lead minerals will be inhibited. Therefore, sodium sulfide should be added in stages. The place of sodium sulfide or sodium hydrosulfide with the addition of copper sulfate, ferric sulfate, sulfuric acid can even eliminate the adverse effects of excess curing agent.
The mineral liquid absorbs the vulcanizing agent and stains the mineral surface, and adds water glass, sodium pyrophosphate and carboxymethyl cellulose to partially overcome the harmful effects of the slime. Sometimes you need to take off the mud, but this will cause the loss of metals.
The gypsum in the gangue causes agglomeration of the slime in the slurry and acts on the carbonate ions to form a precipitate of calcium carbonate covering the surface of the mineral, hindering the vulcanization of the mineral and the action of the collector. There are two ways to eliminate the effects of gypsum:
1 use sodium thiohydride instead of sodium sulfide, or add a small amount of sulfuric acid to reduce the pH of the slurry, so that the carbonate ions form soluble compounds, so as to avoid the formation of insoluble calcium carbonate;
2 Add ammonium chloride or Other ammonium salts to the slurry to increase the solubility of calcium carbonate and limit its precipitation on the mineral surface.
(2) Fatty acid plus neutral oil flotation method This method is suitable for ore with high content of lead minerals and little or no limestone and dolomite in the gangue. The indicators obtained by this method are often lower than the former. However, in some white lead ore mining plants, better indicators can be obtained.
Available fatty acid collector, heavy oil, coal oil and oxidation products of the oil, and naphthenic acid and tall oil soaps.