Hydraulic potential stimulation and bricks preparation of magnesium slag

The hydraulic potential stimulation of magnesium is significant to its direct utilization. In this paper, magnesium slag which is the main material, and some slag and activator are used to prepare cementitious material and bricks, and the influences of different activators on the hydraulic properties are also investigated. Experiments show a certain hydraulic potential of magnesium slag but with a low strength, however, the compressive strength soars from 1.8 MPa to 27 MPa after composing it with a small amount of blast-furnace slag. The early strength of magnesium slag-blastfurnace slag binder is affected by NaOH, while the gypsum affects the binder’s later strength. Bricks conforming to standard MU20 are successfully fabricated by 80% magnesium and 20% blast furnace slag, after activated, with extra 5% desulfurized gypsum.     

An Investigation on Measuring Surface Viscosity of Melting Slag

Several methods of measuring surface vescosity are discussed. An appropriate method for measuring surface viscosity of melting slag- the laser method is proposed as well as an experimental device is set. With the device the surface viscosities of some aqueors liguids are measured. The results verify that the device is feasible and lays a good foundation for measuring the surface viscosity of melting slag.     

Compound Effect of Dihydrate Gypsum and Silica Fume on Strength of Steel Slag-Cement Binding Materials

By adding small amount of dihydrate gypsum (CaSO4·2H2O) and silica fume in steel slag-cement system, steel slag-cement binding materials were prepared. And the dosage of CaSO4·2H2O and silica fume on the properties of steel slag-cement binding materials was studied. Hydration properties and paste structure were investigated by SEM and XRD. The results show that both CaSO4·2H2O and silica fume can improve the strength of steel slag-cement binding materials. Compared with single-doped, compound of CaSO4·2H2O and silica fume has much better effect on strength of steel slag-cement binding materials. The optimum proportion of CaSO4·2H2O and silica fume are 1% and 4%, respectively. The 3 d compressive strength is increased by 59.0%, and the 28 d compressive strength is increased by 36.5%. No matter adding CaSO4·2H2O and silica fume or not, the steel slag-cement binding materials have the same hydration products. However, the content of C-S-H gel and AFt crystals is higher, and the content of Ca(OH)2 crystals is lower in steel slag-cement binding materials containing CaSO4·2H2O and silica fume than those in steel slag-cement binding materials without CaSO4·2H2O and silica fume.     

Viscosity Calculating Model of Iron-bath Smelting Reduction Slag

It is thought that the smelting reduction is one of the advanced technology for metallrugical industry. The constitutes and characters change continuously because the charging is loaded periodically. The influence of slag viscosity is important for smelting process. The foundation of viscosity calculating model is propitious to rapidly forcast the slag viscosity. The viscosity calculating model of melting slag is founded according to the ion theory and the characters of iron-bath smelting reduction slag, the calculating program is finished. The result indicates that the calculating value and the measuring value is approaching. This model can be applied to calculate or forecast the iron-bath smelting reduction slag viscosity.     

Effection and Mechanisms of Composite Binders of Alkali-Activated Slag in Immobilizing of Sr 2+

The effection of composite binders based on alkali-activated slag on the immobilization of Sr 2+ were investigated and mechanisms were analyzed, by way of leaching test, SEM and adsorption test. Results show that the ability of the composite binders on the immobilization of Sr 2+ are influenced by the type and amount of alkalis as well as type of mineral admixtures. The effection of the composite binder on the immobilization of Sr 2+ increased with amount of alkalis increased in the range of 3.0% to 6.0% (count as Na2O equivalent). The binder used water glass as alkalis performed better effection on the immobilization of Sr 2+ than that used NaOH as alkalis. In comparison to kaolin and zeolite minerals, binders contain diatomite has best effection on the immobilization of Sr 2+. Reasons lie in that diatomite has the highest ability on the adsorption of Sr 2+ and could improve microstructure of solified substrate effectively.     

Investigation of Surface Viscosity of BF Slag Bearing High Titania

In this paper the surface viseosity of BF slags bearing high titania has been mea-sured by an experimental device called LASVIM(Laser Surface Viscositymeter)which is designedby authors,and the comparision of the results with the previous works of the authors shows that thesurface visccoity of BF slag containning high titania is depending on its foaming property, Severalfactors on the surface viscosity are also investigated.     

PHASE ANALYSLS OF LOW-VALENCE TITANIUM IN SLAG CONTAINING HIGH TITANIUM

Hcl is used to remove MF4, Fe2O3 and part of FeO. The residue is dissolved by H2SO4-HF-H3PO4. Then, NH4Fe(SO4)2 is added to oxidate low-valence titanium and the standard solution of K2Cr2O7 is used to titrate Fe2+. The amount of total iron minus the amount of iron which has been removed, so that the amount of residue Fe2+ can be adjusted. This method has many advantages such as simplicity, rapidity repeatability.     

Effect of the Carbonation on the Steelmaking Slag-Slaked Lime Mortar

The effect of the carbonation on the properties of the steelmaking slag-slaked lime (SmS-SL) mortar and its mechanism were mainly investigated. Furthermore, the environmental benefits of the SmS-SL mortar were discussed as well. Results indicated that carbonation could strengthen the SmS-SL mortar, reduce its drying shrinkage and improve its soundness. With the increase in the steel slag content, the strengthening effect of carbonation on the SmS-SL mortar is enhanced, but its dry shrinkage reduction effect is weakened. The SmS-SL mortar using steel slag exhibits significant environmental benefits. Its CO2 sequestration-efficiency and steel slag-recycle efficiency respectively reaches 6.4% and 27.8%.     

RESEARCH ON THE HYDRATION HARDENING OF THE GYPSUM FLUIDIZED FURNACE SLAG CEMENT

The hydration and hardening of the gypsum fluidized furnace slag cement is analysed by XRD and mercury pressure porosous meter combining with macroscopic experimental results. The additive, curing system affect material properties and why the water-tolerance is improved.     

An investigation of water quenched solution surface evaporation by the high-temperature slag of a power station

Slag water surface evaporation phenomenon exists in the system of water cooling slag removal. The authors study the relationship between slag water (which is from the JINJIE power plant in Shaanxi)surface evaporation rate and the relative humidity(40%~90%)and the water surface temperature(35-75 ℃),which at an atmospheric pressure and the wind speed is 0.5 m/s,and then obtains an empirical equation. The experiment measures three kinds of concentrations of the slag water surface evaporation rate,and compares the measuring results with those of the pure water surface evaporation rate at the same experimental conditions. According to the comparison results,the authors analyze underlying causes of slag water evaporation from the thermodynamic point of view,that is surface temperature and composition and content changed the surface free energy,thus affects the slag water surface evaporation rate. It is found that water surface evaporation rate is 1.1~1.2 times of the rate of slag water when the temperature is over 50 ℃,while the water surface evaporation rate is slightly higher than that of slag water when the temperature is lower than 50 ℃,and the slag water surface evaporation rate changes in 10% in a certain concentration range.     

Effect of B2O3 on the physico-chemical properties of mold slag used for high-Al steel

A new mold slag with low content SiO2 and high content Al2O3 is designed in order to avoid or alleviate the reaction between Al and SiO2 during the continuous casting of high-Al steel, the acidity of this slag is adjusted by adding B2O3, and the effect of B2O3 content on the fusion property, viscosity property and heat transfer characteristics through the mold slag film of the mold slag is analyzed. The results show that the fusion temperature, viscosity, viscous flow activation energy decrease and heat flux through the slag film increases with the increase of B2O3 content in the range of 4%~10%; temperature time transformation (TTT) diagrams move to longer incubation time with the increase of B2O3, while the crystallization speed of mold fluxes decreases; under this experiment condition, the precipitation of CaF2 crystals can be restrained by the increase of B2O3 content in the mold slag.     

Producing More-color Bricks with Discard Slag of Nanking Steel

In order to change the abut 700 thousand ton discard slag of Nanjing steel group limited company (for short name: Nanking steel ) into utilization material , and utilize them efficiently, fully, without pollution, a series of experiments were carried out on producing more color brick. The BF slag and LD slag and sticky matter were first mixed together, then sprinkled noting, concreted, took off the mold and protected. The process and technology of producing the more color brick was studied. The result shows that the various functions of the more color brick meet the building materials standard.     

Effect of Super Plasticizer on Properties of Alkali-Activated Slag

With polynaphthalene sulphona, lingosulphonate based plasticizer, Sodium gluconate, Mortar plasticizer, C18H29SO3Na, C15H34ClN, the performance of alkali-activated slag mortar was teseed. The results show that lingosulphonate based plasticizer and polynaphthalene sulphona have some plasticizing effect for alkali-activated slag mortar, and the effect of the former than the latter obviously. Plasticizing effect of polynaphthalene sulphona compound mixed with air-entraining agent than single-doped polynaphthalene sulphona obviously. Plasticizing effect of polynaphthalene sulphona compound mixed with lingosulphonate based plasticizer than single-doped super plasticizer obviously. When the same amount of water, lingosulphonate based plasticizer can increase the early strength of alkali activated slag mortar, polynaphthalene sulphona can reduce the early strength. The incorporation of slag in the mix of alkali and super plasticizer can increase the strength of alkali activated slag mortar. Lingosulphonate based plasticizer on the setting time of alkali-activated slag have a greater impact,alkali-activated slag mixed lingosulphonate based plasticizer fluidity smaller through time.     

Using Electro slag Melting Process of Cast Molten Iron To Produce Ductile Cast Iron

This paper introduces experimental results of the ESM of cast iron in the laboratory and pilot plant based on predecessor's work by molten CaF 2-based slag systems containing MgO , CaO and RexOy. The results show that the desulfurization ,inclusion removal and gas elimination of the ESM have obvious effects on making iron liquid purified and producing high quality casting ,and indicate that the ESM of cast iron may essentially improve the traditional process of cast molten iron melting as a new technique for making high quality ductile cast iron.     

Properties of Portland Cement with Magnesium Slag

Two kinds of magnesium slag from different places were added in clinker respectively to manufacture portland cement, and the essential properties of cement, such as water requirement of normal consistency, setting time and strength, were studied. The influence of magnesium slag on the drying shrinkage of portland cement was investigated. Meanwhile, effects of magnesium slag in portland cement were analyzed on the basis of XRD, DSC/TG and SEM microscopic experiments. The results show: magnesium slag plays roles in water-reducing and set-retarding as a composite material of cement; when the contents of magnesium slag range from 10%～30% (weight ratio) and 35%～40% (weight ratio), cement samples reach Composite Portland Cement 42.5R and 32.5R standard, separately; the drying shrinkage of mortar can be restrained as the contents of magnesium slag range from 30%～40%; and the structure of cement pastes is more compacted as magnesium slag reacts with the hydrations of clinker.     

改性钢渣的制备及其吸附除磷性能

研究了改性钢渣吸附除磷影响因素、等温吸附线特征和吸附动力学,并对生物处理后的出水进行吸附除磷研究。结果表明：在初始磷浓度10 mg/L,投加量10 g/L、pH为7时,改性钢渣吸附后总磷浓度为0.687 mg/L,去除率达93%;改性钢渣对磷的吸附符合Langmuir模型,理论饱和吸附量是1.977 mg/g,吸附动力学符合准二级动力学模型（R²>0.99）;实际生活污水的吸附除磷中,投加量为50 g/L,反应2 h后出水总磷浓度达到《城镇污水处理厂污染物排放标准》（GB 18918-2002）一级B标的排放要求。