Study Of The Electrolytic Manganese Residue Cementing Material And Its Application

Electrolytic manganese residue(EMR) is a kind of industrial solid waste with a high water content and sulphates content and a good fineness from production of manganese in electrolyzing the manganese carbonate with sulphuric acid, which caused seriouse contamination to the environment of the enterprise nearby. As a high-sulphate-content clay-like material, there is always a lack of breakthrough in the utilization of it, unfortunately, there are lots of misunderstandings of the basic propertie-study. According to the mineral composition of the waste, the EMR can be applied uttely well as a sulfate activator of pozzolanic materials.The basic properties, especially the states of sulphates in EMR were pilotly studied in the eye of utilization as a building material with various kinds of analytic tools. Meanwhile, in order to give good use of its rich contain of sulfates, it was studied that EMR was applied as a sulfate activator to fly ash, as well as EMR cementitious material and its application. As a result, it provided a very necessary reference to the application of EMR in building materials.The results showed that: (1) The EMR is a kind of aluminate-silicate mineral with content of SO3 ranged from 18% to 28%, and content of water between 30% and 40% and a high proportion of particle size less than 80μm. Differently, gypsum was not the unique state of sulphates in EMR as gernerally regarded, the resolvable sulphates consist about 25% of the total. (2) It was significant that EMR was pretreated . It was not only beneficial to the dispersion of EMR , but also be helpful to reducing the residual Mn2 + and NH4+ ions in EMR . (3) The effect of EMR to activate fly ash was researched for, and it showed that the content of EMR pretreated with 7% pretreatment agents is 30%. The influence of cement content on the mechanical properties of composite cementitious material was great, and the constant temperature of cementing materials was 60℃. In addition, it was no toxic effect that cementing materials were in neutral environment environment. The mainly cementitious hydration products were hydrated calcium silicate gel (C-S-H) and ettringite (AFt). (4) The EMR cementing material could be used to produced bricks with excellent performance and EMR concrete which be applicated to rural road with perfect performance.