Study On The Treatment Of Wastewater From Sulfur Chemicals By Using Waste Stone Powder And Utilization Of Its By-product

The new two stages treatment processing technology of sulfur chemicals wastewater by using marble polishing powder and lime, and the effect of the properties of by-product gypsum from the processing as the retarder of cement were studied in the paper by XRD and SEM. The results showed that:(1) The marble polishing powder which mainly contained calcium carbonate could partly replace the lime to neutrailize the wastewater of sulfur chemicals. In the processing of treatment of wastewater of sulfur chemicals by using the new two stages technology of marble polishing powder and lime, the pH value of water processed by the marble polishing powder in the first stage should be control at 4.8-5.5 was better; when the pH value of water neutrailized by the lime in the second stage was at 8.3-8.5, the contain of Fe2+ in the wastewater was very low, and the COD and the colority of the blow-down water could preferably come up to the standard.(2)The setting time of cement mixed–in by- product gypsum as retarder was close to those of the cement mixed–in dihydrate gypsum and the cement mixed–in by-product gypsum & dihydrate gypsum as retarder, because their SO3 dissolution rate in the CaO solution were close.(3)The strength of ordinary Portland cement mixed–in by-product gypsum as retarder was higher than that of the ordinary Portland cement mixed–in dihydrate gypsum as retarder, because the calcium carbonate in the by-product gypsum would participate in the hydration reaction and formed the calcium aluminum oxide carbonate hydrate, which was helpful to improve the cement strength during the cement hydrated reaction. And the strength of ordinary Portland cement mixed–in by-product gypsum & dihydrate gypsum as retarder was slightly higher than that of the ordinary Portland cement mixed–in dihydrate gypsum as retarder.(4)The saturation dosage point of MII naphthalene-type water reducing agent of cement mixed–in by-product gypsum was higher than that of the cement mixed–in dihydrate gypsum, the 5min Marsh time and 60min Marsh time were longer. The compatibility between cement mixed–in by-product gypsum & dihydrate gypsum and MII naphthalene-type water reducing agent was better than that of cement mixed–in by-product gypsum. Considering the setting time, the strength and the compatibility of MII naphthalene-type water reducing agent, the properties of the cement were better when we mixed by-product gypsum & dihydrate gypsum as cement retarder.The way of using the marble polishing powder as one of the material to neutrailize acidic wastewater of sulfur chemicals and using the by-product gypsum as the retarder of cement can save the resource and reduce the waste, and forms the regional distinctive the stone industry, sulfur chemicals industry and the cement industry circular economy industry chain.