Papers by Keyword: Slag

Abstract: Paper is focused on development of hydration heat in concrete in time. Possible ways of reduction of temperature during concrete hydration are mentioned. Paper presents study of possibilities of regulation temperature in concrete during hydration by selection of suitable input components. Blast furnace slag and micronized limestone were added to pure Portland cement; several variants of proportions were proposed.

Abstract: The quantitative phase analyses of a slag have been successfully carried out by using both of the full-profile Rietveld and RIR methods from X-ray powder diffraction data. The qualitative phase analysis indicates that the slag contains mayenite (CaO)₁₂(Al₂O₃)₇, olivine Ca₂(SiO₄), gehlenite Ca₂Al (AlSiO₇), lemite Ca₂(SiO₄) and hibonite CaO(Al₂O₃)₆. The quantitative analysis from Rietveld refinement shows that the weight concentrations of mayenite, olivine, gehlenite, lemite and hibonite for the slag are 48.8(4) wt.%, 32.2(5) wt.%, 11.0(9) wt.%, 6.2(1.1) wt.% and 1.8 (1.2) wt.%, respectively. The quantitative phase analysis results obtained by Rietveld method are more precise then those by RIR method.

Abstract: In early research based on the study of gypsum, slag and other cotton stalk fiber composite of wall, by mixing EPS beads developed a lightweight, insulated, has a certain strength of new wall multifunctional composites. The material use EPS as insulation particles aggregate, slag as aggregate, cement and gypsum as matrix,through mixed with straw fibers of crushed cotton to solve inorganic and organic materials interface bond strength is low and EPS particles floating problems, In order to trial a kind of good performance of the wall material.

Abstract: In order to investigate the activity of different original slags and the coupled relation between the slag and the clinker, the simplified slag cement system was designed in the experiment, in which clinker was replaced by lime.The reactional degree of slag in cement was determined through using chemical combined water content method, and the hydration processs were determined through using DSC-TGA. The results showed that for the different original slags, the destruction and rebuilding process of their microstructure were important to distinguish the activity of slags. And the process of slag hydration mainly experienced two stages, including microstructure destruction at early ages and microstucture rebuilding at later ages. And the variation of Calcium hydroxide content in cement indicated the interaction between the slag and clinker, and slag may improve the clinker hydration velocity.

Abstract: At present, the Narrow Gap Submerged Arc Welding is an advanced welding technology. As the weld is very deep and narrow, the slag is difficult to clean and will have impact on the quality of welding seam. Therefore, a new kind of narrow gap submerged arc welding slag cleaning device is designed to clean the welding slag. It is consisted of welding walking tractor, height adjuster, slag masher, slag cleaner and slag collector. The narrow gap submerged arc welding slag removal device used for the welding process can realize the cleaning that manpower cannot finish. It is a kind of time-saving, energy-saving and high efficient welding cleaning method.

Abstract: Chromite and laterite ores from local sources were smelted in a vertical tube furnace with activated carbon as reducing agent at 1400°C to 1550°C using graphite crucible under argon atmosphere. It is shown that the grade and composition of the ore are the main factors determining the feasibility of smelting a mixture of chromite and laterite ores to produce a Fe-Ni-Cr crude alloy. The high recovery of iron and nickel in the alloy indicates the highly reducing condition prevailing in the smelting reduction experiments. It is also shown that the solubility of Ni in the slag increases with Ni concentration in the alloy and the FeO concentration in the slag. The chromium content of the slag increases with increasing iron content of the slag.

Abstract: The technology was used for handling aging oil by demulsifier thermal chemical deposition and horizontal scrow centrifuge. Under certain temperature, The heavy aging oil, mixed with a certain Demulsifier for demulsification, is loaded into the packaging three-phase Horizontal Screw Centrifuge for oil, water and soil separation, the water content of processed oil dropped to 10% below which meet oil remix and fuel oil requirement. The influence of liquid level adjusting board, the handling capacity, processing temperature and operating parameters of centrifuges are all discussed as well.

Abstract: C30 concrete has been universally used. To improve its quality, the author of this paper made an experiment so as to obtain the optimal proportions of flag, fly ash and silica fume in green concrete. She used granulated blast furnace slag, fly ash and silica fume as concrete admixtures by means of equivalent replacement of cement, mixed them with water reducing agent. She compared the maximum compressive strengths of concretes with different ages and minerals in four schemes and obtained their respective optimal proportions: (1) when slag dosage is 35%, fly ash is 10%, the maximum compressive strength values of concrete with different ages are 27.4 Mpa, 38.6 Mpa, 40.6 Mpa and 45.1 Mpa; (2) when slag dosage is 35% and fly ash additive is 10% and water reducing agent 1%, the maximum compressive strength values with different ages are accordingly 42.3 Mpa, 43.8 Mpa, 46.3 Mpa and 47.0 Mpa; (3) when 30% of fly ash alone is added and 1% of water reducing agent is added, the maximum compressive strength values with different ages are 35.3 Mpa, 39.0 Mpa, 39.8 Mpa and 43.1 Mpa; (4) when fly ash is 30%, slag 20%, silica fume 10% and 1% of water reducing agent is added, the maximum compressive strength values with different ages are 37.2 Mpa, 38.7 Mpa, 40.0 Mpa, and 44.4 Mpa. In addition, the role of performance and mechanism of the above admixtures and uses of green concrete are also expounded..

Abstract: According to the intuitive analysis and variance analysis of L₁₆ (4⁵) orthogonal experiment, the activity of slag was investigated on component of compound activator and mixing amount with the compressive strength as evaluation standard of various influencing factors. The results show that the range of anhydrous sodium sulfate (NS) was maximum, clinker (NL) comes second and lime (NH) was minimum, which means that primary and secondary of compound activator to the compressive strength of slag cementations material was NS>NL>NH, and the better activated effects can be obtained as NS=4%, NL=0.6% and NH=0.6%.

Abstract: The microstructure and impurities distribution in metallurgical grade silicon with treated by CaO-SiO₂ and Na₂O-SiO₂ slags were investigated. An exhaustive analysis of the transformation of precipitated phase at grain boundaries has been carried out. Prior to slag treatment, Si-Fe system intermetallic was the primary precipitated phase in metalllurgical grade silicon. After treated by CaO-SiO₂ slag, Si-Ca system intermetallic became the main precipitated phase, such as Si-Ca, Si-Ca-Ti, Si-Ca-Al and Si-Fe-Ca. But Na₂O-SiO₂ slag had another result on refining metallurgical grade silicon; only Si-Fe-Ti phase was generated in precipitated phase and the low level of sodium in treated silicon was obtained.