胶东铁路弃土弃渣体产流产沙特征

通过人工模拟降雨试验,研究降雨强度和坡度对胶东铁路弃土弃渣体产流产沙的影响。根据青荣铁路沿线降雨和弃土弃渣体堆积特点,设计3种雨强(20,40,60mm/h)和3个坡度(20°,30°,40°)。结果表明:(1)当降雨强度由20mm/h增加到60mm/h,产流开始时间可缩短11~20s;当坡度由20°变化到40°,产流开始时间可提前17~22s。(2)径流量、产沙率在降雨初期剧增到峰值,之后径流量逐渐趋于稳定,而产沙率波动减小后逐渐趋于稳定。(3)相同坡度条件下,雨强40 mm/h下的径流量较20 mm/h时增加37.3%~122.6%,产沙率约为20mm/h时的1.5~19.5倍;而雨强60mm/h下的径流量较40mm/h时仅增加19.1%~26.7%,产沙率仅为40mm/h时的62.5%~151.8%。(4)相同雨强条件下,坡度对径流量、产沙率的影响存在临界坡度(30°~40°),径流量、产沙率随坡度的增大先增加后减小。(5)弃土弃渣体坡度为30°时坡度对坡面侵蚀量的贡献率大于雨强贡献率;而40°时雨强贡献率明显超过坡度。研究结果可为胶东半岛区域铁路项目建设期间弃土弃渣体的水土流失监测及防治提供技术支撑。     

真空碳热还原酸浸含钛高炉渣制备TiC分析

含钛高炉渣中含有20%~30%的TiO 2,是一种附加值较高的二次资源,但在综合利用过程中存在氧化物还原难度大,硅钛难分离,二次污染严重等问题。基于热力学理论基础,采用真空碳热还原联合酸浸工艺处理含钛高炉渣制备TiC。结果表明：真空有助于钛氧化物彻底还原,可实现渣中硅钛彻底分离,减少酸耗量,降低二次污染。真空碳热还原联合酸浸工艺处理含钛高炉渣(TiO 2含量23%左右)制备TiC的最佳条件为：炉渣粒度200目,还原温度1 673 K,渣碳质量比100∶38。     

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.     

水稻土施用钢渣硅钙肥对土壤硅素形态和水稻生长的影响

钢渣是钢铁厂的副产品,富含硅、钙等养分,是优良的硅钙肥原料。但钢渣为强碱性物质,在稻田施用后对土壤p H值及硅素形态的影响需要阐明。2013年3―12月,通过早稻~晚稻连续2季钢渣硅钙肥温室盆栽试验,研究了钢渣施用对土壤p H值、土壤硅素形态以及水稻生长和植物硅素吸收的影响。结果表明,随着钢渣硅钙肥施用量的增加土壤p H值、土壤水溶性硅量、土壤有效硅量以及植株秸秆硅量均呈增加趋势,当土中施用钢渣有效Si O2用量高于1 600 mg/kg时(Si4和Si5处理),上述指标均显著高于CK。土壤无定形硅量随钢渣施用量的增加则表现出降低趋势,无定形硅量与有效硅量呈显著负相关关系。施入钢渣硅钙肥促进了水稻的生长发育,在2季水稻中,Si4和Si5处理秸秆+叶片干物质量较CK提高了11.9%~17.0%,籽粒干物质量较CK提高了9.52%~20.6%。     

养护制度和大掺量掺和料对混凝土干缩性能的影响研究

养护是获得高性能混凝土的重要环节,针对混凝土所处的环境特点,研究了大掺量矿渣和粉煤灰混凝土的干缩性能以及养护制度对混凝土干缩性能的影响规律。结果表明,在相同养护制度下,掺矿渣和粉煤灰的混凝土各测试龄期干缩率相对基准混凝土试件减小约5%～20%,有利于改善混凝土的干缩性能;延长养护时间有利于改善混凝土的干缩性能,养护时间宜根据需要适当延长,一般情况下不宜低于3d,且养护时间和养护方法对大掺量掺和料混凝土显得尤为重要。     

Magnesium slag for remediation of cadmium- and arsenic-contaminated paddy soil: A field study

The accumulation of heavy metals like cadmium (Cd) and metalloids like arsenic (As) in plants can do harm to human health through the food chain, especially through the rice (Oryza sativa L.). To solve this problem, this study researched the application of magnesium slag (MS) and polyaspartic acid (PASP), which could accelerate rice growth and improve yield, increase soil pH and activate rice enzyme activity as well as reduce the bioavailability of Cd and As in the soil. After these two different treatments, rice yield increased by 17.0% and 18.9%, respectively. Meanwhile, the bioavailable As decreased by 49.1% and 42.5%, while the bioavailable Cd reduced by 72.6% and 44.3%. Besides, the Cd content in rice grains reduced by 77.7% and 17.3%, respectively, after two different treatments. In the MS treatment, the As content in rice grains was reduced by 21.8%, but showed no significant response to the other treatment. The contents of bioavailable Cd and As (determined by one-step extraction) in soil were decreased by MS and PASP, which was favourable for the reduction of Cd and As accumulation in rice. The health risk assessment showed that the application of passivators can effectively reduce the risk of carcinogenesis, but it was still unacceptable. The application dose of MS and PASP still needs further exploration.     

A simulated experiment on the high titanium slag rheological behavior

The rheological property of high titanium slag is a main factor to influence the vanadium titanomagnetite smelting in blast furnace. It plays a great role in discharging slag, separating iron and slag and even the life of blast furnace hearth. The acrylonitrile-butadiene-styrene multipolymer(ABS) dense suspension is taken to simulate the system of high titanium slag. Apparent viscosity is measured by a NXS-11A rotating cylinder viscometer. The impact of temperature, volume fraction and particle sizes on the suspension apparent viscosity is studied. The results show that temperature and volume fraction have a strong influence on the suspension apparent viscosity, while the particle size has a weak effect. The suspension shows Bingham behavior within a wide concentration range. The dependence of the appear viscosity on temperature and amount of solid addition can be described by a binary function equation.     

蒜渣碱提多糖体外抗氧化性的研究

研究蒜渣碱提多糖对DPPH·,羟自由基、超氧自由基的清除以及抑制猪油和芝麻油快速氧化的效果。当多糖与DPPH·质量比为1.6时,电子顺磁共振(ESR)测定5 min就检测不出DPPH·;当多糖质量浓度为0.16 mg/mL时,可以清除50%羟基自由基;当质量浓度为0.2 mg/mL时,可以清除50%的超氧自由基;多糖对猪油和芝麻油的氧化都有一定的抑制作用,当浓度增加时,抑制效果增强。     

Quantitative study on solid slag film’s crystallinity of mould fluxes by using DSC method

The method to determine the crystallinity of solid slag film is established by analyzing the DSC curve of solid slag film and corresponding quenched slag. The accuracy of the method is investigated by measurements of prepared samples whose crystallinity is given. In addition, the solid slag films of mold slags used to cast medium carbon steel and low carbon steel are obtained by heat flux simulator in laboratory, and the crystallinity of the two kinds of slag film are also measured by DSC method. Experimental results indicates that the crystallinity of solid slag film can be determined by comparing the crystallization enthalpy of solid slag film and corresponding quenched slag during heating process, and the relative error is within 5.03%. For medium carbon steel, the crystalline fraction of solid slag film is 88.6%, while the crystalline fraction of solid slag film corresponding to low carbon steel is 55.0%. The results are consistent with actual structure of solid slag films.