从化学加工工艺谈磷矿物的分类及其意义

作者认为磷矿物是以固溶体形式出现的一组含氟磷酸钙盐,多种矿物盐的组合常以其最为稳定的形式,即能量最低的状态存在。因此,作者对磷矿物的分类不是从矿物类型而是以能量方程式所具有的特征系数进行分类。根据矿物类型建立P_2O_5枸溶率、晶胞参数a_0轴的模拟方程。分类结果:自然界的磷矿物共分高氟磷灰石、富氟磷灰石、低碳氟磷灰石,氟磷灰石和低氟磷灰石五类。由于磷矿物中的氟含量直接影响了磷矿物的各种性质,而磷矿煅烧(包括脱氟磷肥生产)过程实质上是模拟磷矿在自然界的变质过程,使P_2O_5枸溶率和化学反应性下降。因而可根据本文分类对磷矿物的应用进行直接评价。

石英压力传感器石英材料的加工工艺

提出了石英压力传感器中石英膜片的化学加工方法,从选材、原理及工艺设计、关键加工步骤及过程控制方法等方面进行了研究,并通过相关制作与实验证明该种加工工艺方法简单,具有一定的实用性.

Non-isothermal Kinetics of Pyrolysis of Three Kinds of Fresh Biomass

The pyrolysis kinetics of three different kinds of fresh biomass (grass: triple A, wheat straw, corn straw) in nitrogen flow were studied by thermogravimetric analysis at five different heating rates. The kinetic parameters of the pyrolysis process were calculated using the method of Ozawa-Flynn-Wall and the mechanism of reactions were investi- gated using the method of Popescu. It was found that the values of activation energy varied in different temperature ranges. The pyrolysis processes are well described by the models of Zhuravlev (Zh) and valid for diffusion-controlled between 200 ℃ and 280 ℃, by Ginstling-Brounshtein (G-B), valid for diffusion-control between 280 ℃ and 310 ℃, for first-order chemical reaction between 310℃ and 350 ℃, by Zhuravlev (Zh) valid for diffusion-control between 350 ℃ and 430 ℃ and by the one-way transport model when temperatures are over 430 ℃.

FEM analyses for influences of stress-chemical solution on THM coupling in dual-porosity rock mass

The models of stress corrosion, pressure solution and flee-face dissolution/precipitation were introduced. Taking a hypothetical nuclear waste repository in an unsaturated dual-porosity rock mass as the calculation objective, four cases were designed 1） the fracture aperture is a function of stress corrosion, pressure solution and free-face dissolution/precipitation; 2） the fracture aperture changes with stress corrosion and pressure solution; 3） the fracture aperture changes with pressure solution and free-face dissolution/precipitation; 4） the fracture aperture is only a function of pressure solution, and the matrix porosity is also a function of stress in these four cases. Then, the corresponding two-dimensional FEM analyses for the coupled thermo-hydro-mechanical processes were carried out. The results show that the effects of stress corrosion are more prominent than those of pressure solution and free-face dissolution/precipitation, and the fracture aperture and relevant permeability caused by the stress corrosion arc only about 1/5 and 1/1000 of the corresponding values created by the pressure solution and free-face dissolution/precipitation, respectively Under the action of temperature field from released heat, the negative pore and fracture pressures in the computation domain rise continuously, and are inversely proportional to the sealing of fracture aperture. The vector fields of flow velocity of fracture water in the cases with and without considering stress corrosion are obviously different. The differences between the magnitudes and distributions of stresses within the rock mass are very small in all cases.

硬质合金枪钻刃口新型钝化工艺的电解规律实验研究

针对硬质合金枪钻刃口钝化的效率低、钝化轮损耗高、刃口形状难控的现状,本文提出将电化学方式与机械方式复合运用到硬质合金刀具刃口钝化中,并对这一钝化工艺方法做探索性的实验研究。实验分为电解和机械去除两道工序,并以电化学过程的机理研究为重点。实验将其他参数固定,选择电压值U和通电时间t为变化参数。实验测量每个参数组合下,刀具刃口形状及刃口半径值。由实验数据及图片得出电解钝化效率,电解电压在14～21 V之间时,电解部分以通电时间t=10 s为界限,5～10 s之间呈上升趋势,10～21 s之间呈近似水平线趋势。经过总结、对比实验结论,证明此工艺方法可控、高效、低耗等优点,可解决硬质合金刀具刃口钝化现存的问题。

采用石灰法处理磷化废水

汽车磷化处理是对汽车的钢铁零件表面进行的一种化学加工工艺，其废水中含磷量高，超标严重。磷化废水的处理有多种处理方法，需要通过研究和实验获得最经济和最有效的处理方法。