Research On Silicate Aluminum Slag Containing Modified Lithium Concrete

This paper studies that lithium slag with main ingredients of amorphous silica, alumina, through appropriate physical and chemical modification process to change the nature of lithium acid residue, to be modified powder with non-steady state (amorphous and crystalline - state) silicate, aluminate and silicate, appropriate to the Alkali activation,be made hydraulic cementitious materials.Three major studies of alumino- silicate concrete : the light alumino- silicate concrete of lime-physical modification (LWEC); alkali alumino- silicate concrete of slag-chemical modification of lithium slag(JHEC); alkali alumino- silicate aerated concrete (AHEC).Using two methods of physical and chemical, the residue of lithium is to be modified. Modification of the physical: adding some lime, and calcium additive to improve the alkaline and reform effect by mechanical grinding is to be modified powder.Using atmospheric dry cured, the physical modified powder as a cementitious material is made to produced light silicate concrete (LWEC).Chemical modification: by modifier to Li slag, after high calcining temperature 1000℃modified, then rapidly cooling and grinding, has to be modified chemical powder. Microscopic observations show: particles are smaller and spherical category, Overall show honeycomb structure. Compareing with Li slag, has been a complete change in the morphology. Chemical modification powder drop alkali slag mortar, can significantly improve the performance of alkali slag mortar (JHEC).Chemical modification powder can be used as the main components ,to prepared alkali alumino- silicate aerated concrete (AHEC).Results of this study are as follows:①Lightweight high strength concrete of lithium aluminate of the physical modification of the lithium slag in the atmospheric dry-curing conditions, compressive strength can achieve about 40～50MPa , flexural strength up about 9～11Mpa. Finally prepared lightweight high strength concrete is about 1600kg/m~3 dry density. The optimum parameters: the heating rate of 30℃per hour, the lasting temperature of 180℃, the lasting temperature for 4 hours. Initial energy consumption Calculation, with the same level of intensity autoclaved light gray sand concrete , atmospheric dry -wet cured than autoclaved cured to save more than 45% of energy, lower around 11% dry density. ②Experimental results show that Calcined modified lithium slag optimum process parameters is, calcination temperature of 1000℃, calcination time of 45min,after rapid cooling and grinding 15min to be modified products. The powder is fine, specific surface area 7350cm~2/g～8348 cm~2/g.Powder packing density is 2.1 g/cm~3～2.3g/cm~3, density of 2.4g/cm~3 -2.6 g/cm~3.③Chemical modification powderAF3 by adding alkaline slag mortar(JHEC), the mortar can improve performance. When the incorporation of modification powder from 10% to 20%, it will boost alkaline slag mortar strength and extend time. When the incorporation of 30% modified powder, the concrete 28d strength development better than pure alkaline slag mortar, but almost 56d strength of the development. The modification powder increased gradually more than 40%, the mortar strength begin to decline. While the incorporation of 60% modification powder , bending and compressive strength is low 46.2%,38.4% than the pure mortar slag. But specimens strength is with strength32.5 grade Portland cement.The study found that the powder can significantly inhibited dry shrinkage, caused by dry slag cementitious materials. By calcinations, the modified powder reached the right synthetic modification slag cementitious materials.④Through X-ray Diffraction and Scanning Electron Microscopy to view, it find that in the JHEC paste the hydration product is most zeolite minerals. From the crystallization, in the JHEC paste, slag particles hydration is more thoroughly and more conducive cementing to form a whole.⑤Successfully the work is make to get the alkali silicate Aerated Concrete (AHEC),to get the optimum process parameters. In the experiment steam conservation, water conservation and standards conservation is used as three conservation approaches in the experiment and is drawn three optimization conservation parameters approaches. It found that steam conservation is best than the other two.⑥After testing, it shows that shrinkage properties, water absorption, water conductivity and thermal properties of the steam conservation specimen are meet the autoclaved aerated concrete block national standard (GB 11968-2006).The main study how efficient to use acidic residue, accumulation a large number of lithium is to new use, improve the added economic value.Sum up the typical acidic residue on the modified method and its application of the law, Guidance on acidic industrial waste to the development and application. So it has a good practical significance...