Research Of Electrolytic Manganese Residue Properties And Utilization

Electrolytic manganese residue(EMR) is produced in the hydrometallurgical process of manganese ore. With the increasing demand for the base material manganese in metallurgy, aerospace, chemical and other industrial, coupled with low taste of manganese ore, there has an increasing production of EMR. The EMR disposed on the industry are usually open dumps, which not only take up a lot of land resources, a high concentration of waste water leaching will cause soil contamination, soil compaction. On the condition of leaching and rain, it can also cause manganese and ammonia exceed standard, and there is debris flow hazards, which caused a lot of environmental problems.In order to reduce its impact of leaching toxicity on the environment and improve the mix in cement products, on the premise of analysis of the basic properties, the full amount and form, leaching toxicity of EMR, this paper using alkali activation technology to process EMR preparation of cement admixture, which designed to open a new direction for the treatment of EMR. Through the experiment, we can get the following conclusions:The EMR used in this experiment as a black viscous industrial solid waste, with a density of 1.951 g / cm3, moisture content of 27.28%, an average pH value of about 6.08, acidic. The main elements in EMR include oxygen, silicon, sulfur, calcium etc. And most of the chemical composition of EMR is clay mineral suah as the SiO2, SO3, CaO, Al2O3. Moreover, the EMR has no volcanic activity.The amount test of heavy metals in EMR showed that the Mn, Pb, Zn, Cu has more levels, the content of Mn up to 48825 mg / kg. And morphology test of heavy metals in EMR showed that in exchangeable Cd and Mn had the highest content, whereas carbonate bound Zn, Cd, Mn had highest content, and iron-manganese oxide bound mainly as Mn, Zn, and organic bound mainly as Zn, Cd, Cu, while the content of Cr,Pb, Ni, Cu were highest in residual. the content of other morphology of Cr are below the detection limit that not be detected except the residual.Leaching toxicity test showed that: the oscillation mode had great influence on the leaching concentration of EMR for the same metal ions. And flip oscillation was more conducive to the dissolution of metal ions. The leaching concentration of each metal reached the maximum in the liquid / solid is 5: 1, the leaching concentration of each metals show the trend of reduced total with the increase of liquid/solid, and the reduced rate slow down after quickly. The concentration of each metal showed a decreasing trend overall with the increase of pH, and acidic environment was more conducive to the dissolution of metal ions.Using alkali-activated EMR partly replace of cement prepared cementitious material experiments mainly studied the effect of alkali-activated, curing conditions for the compressive strength of alkali-activated EMR and cement system. Orthogonal experiment showed that when water-cement ratio 0.38,75 oC conserved 12 h, the admixture compose with 85% cement and 15% EMR which was activated by NaOH(the Na2 O equivalent is 10%),the compressive strength for each age of the specimens were maximum and up to 29.03 MPa,37.14 MPa,45.08 MPa respectively. That is to say, in terms of the compressive strength, the use of EMR partly replace traditional Portland cement as cementitious is feasible.