不同膨润土对模拟酒溶液中蛋白质的吸附

The adsorption of protein from model wine was investigated under different temperatures, pH values, contact times, and concentrations of ethanol, by certain bentonites. The results showed that ethanol molecules could broaden the protein molecules＇ channel to the interlayer of bentonite, and the maximum protein adsorption amount occurred under an ethanol concentration of 12% （by volume） and a pH value of 3.56. The increased single point Brunauer-Emmitt-Teller （BET） surface area （SBET） and adsorption pore volume （VAds） suggested a larger amount of active adsorption sites of the bentonite surface and a wider protein channel from the surface to the inner adsorption sites of bentonite, respectively. At the same time, higher methylene blue test （MBT） and swelling index （Sw） indicated that it was easy for the entrance of water and the absorbance of protein. Higher temperature was found favorable to eliminate more proteins and it took about 20 to 40min to arrive at the maximum adsorption.     

钼蓝光度法测定铁矿中磷含量

采用磷钼蓝光度法测定铁矿中磷含量,优化显色条件、采用酒石酸钾钠掩蔽,抗坏血酸还原,使配合物更稳定,分析结果的准确度和精密度满意。     

滴定分析法测定铁矿中亚铁含量

采用硫酸氢氟酸溶样对铁矿中亚铁含量测定进行了探讨。考察了酸种类、溶样时间对铁矿中亚铁含量测定的影响。实验表明,硫酸氢氟酸进行溶样,溶样时间控制在10min时测定结果较好。     

活性白土对模拟油脂中β-胡萝卜素和叶绿素的吸附动力学研究

The textural properties of acid-activated bentonite (AAB), which were prepared using four different concentrations of sulfuric acid, were analyzed by adsorption-desorption isotherm of nitrogen using an automated specific surface area and porosity analyzer. The total pore volume, specific surface area and average pore diameter of these four kinds of AAB show a regular changing trend, increasing first and then decreasing, the optimum of which can be achieved at a sulfuric acid concentration of 25% (sample A25). The kinetic analysis of the adsorption ofβ-carotene and chlorophyll in model oil solutions, namely, xylene and edible oil solution, has been investigated by using AAB. Experimental results indicated that the adsorption data fit the pseudo-second-order model well. The whole adsorption process of the two pigments on AAB was divided basically into two parts the initial adsorption of pigments was rapid in the first 10 min, followed by a slower adsorption process till equilibrium was attained at 60 min. In addition, the amount and rate of adsorption on A25 increase synchronously with the initial pigment concen-tration and temperature. The results showed that the adsorption kinetics behavior of AAB with respect to the pig- ments is not influence by the xylene and edible oil solution.     

日月雷矿膨润土提纯影响因素分析及产品性能表征

利用物理和高速离心的方法对新疆夏子街地区日月雷矿膨润土进行提纯研究,考察了液固比、制浆时间、离心转速和离心时间等影响提纯效果的主要因素,结合正交实验确定出了日月雷矿膨润土提纯的最优条件。提纯后产品的品位有较大程度的提高,其膨胀容、蒙脱石含量、交换阳离子总量分别由53.8ml/g、68.5%、64.9mmol/100g提高到89ml/g、96.6%、98.4mmol/100g,而且Ca2+、Mg2+离子含量均有不同程度的降低。同时,样品的单层BET比表面积从57.99m2/g提高到71.14m2/g,有效吸附表面增大,改善了产品的吸附性能。     

改型膨润土对红葡萄酒澄清过程中蛋白质和色素的影响

利用改型膨润土对红葡萄酒原酒进行澄清,主要考察了膨润土添加量、不同澄清时间以及不同pH条件下葡萄酒的澄清效果,结果表明:膨润土的最佳添加量为0.4g/L时即可达到良好的澄清效果;膨润土对葡萄酒的澄清在最初的8h内作用明显并且应尽可能在较低的pH条件下进行,这样就会有更多的蛋白质带正电荷,与带负电荷的膨润土表面产生电荷吸引,从而使蛋白质沉淀,有利于保持酒体的长期稳定。     

不同酸化剂对乌兰林格膨润土活化效果的影响

考察了不同加量的磷酸、硫酸和盐酸对乌兰林格白色钠基膨润土的活化效果,表明磷酸活化产品游离酸在0.302%～0.869%之间,远高于硫酸的0.026%～0.070%,其脱色率远低于硫酸、盐酸活化产品.硫酸和盐酸在加酸量分别为25%和30%时产品有最高的脱色率,综合考虑确定硫酸为最佳酸化剂.不同酸化剂活化产品的活性度和游离酸随着加酸量的增大而变化的趋势基本一致,活性度出现最大值时所需的加酸量比脱色率出现最大值时的要小,松散密度与脱色率总体呈反向变化趋势.     

新疆夏子街膨润土的特性及其酸活化产品脱色性能的研究

Bentonite produced in Xiazijie, Xinjiang （China） was characterized by X-ray diffraction （XRD）, differential thermal analysis （DTA）, thermogravimetric analysis （TG） and cation exchange capacity （CEC）. The bentonite is composed of dioctahedral montmorillonite with predominant quantity, certain amounts of quartz, feldspar and illite and minor amounts of kaolinite, gypsum, etc. The raw bentonite has a CEC of 0.6497 meq·g^-1 and allows to be characterized as typical sodium bentonite. In order to bleach cottonseed oil, optimum conditions for sulfuric acid activation of the raw bentonites were investigated, which were obtained by selecting various acid strength, at 96-98℃ and activating for 4h with 1 ： 2 solid-liquid ratio. The acid activation bentonites were suitable for decolorization of cottonseed oil through removing carotene and chlorophyll. The bleaching capabilities of different pigments with activated bentonite with treatment of 25% sulfuric acid were 70.3%, 73.1%, 83.2%, 81.8% and 88.9%, respectively. Bleaching with acid activated bentonite gave oils lower peroxide values and acid values.     

膨润土在食品工业中的应用

膨润土是一种重要的化工原料，由于其独特的晶体结构，具有较大的表面积、较强的膨胀性、吸附性及脱色能力，经提纯或改性后广泛用于食品工业中如油脂、酿酒、饮料和调味品等的脱色澄清处理。本介绍了膨润土的晶体结构、基本特性及吸附脱色机理，同时，重点综述了其在食品工业中的应用研究，并展望了其应用前景，为膨润土产品的研发及应用领域的拓宽提供了依据。     

提纯活化联合工艺制备高效活性白土的研究

研究表明一次提纯土和二次提纯土的蒙脱石含量比原矿分别提高了27.12%和32.65%.在活化温度95-98℃、固液比为1:3、活化时间为5h的条件下,得出一次提纯土加酸量60%制备的活性白土性能较好,脱色率99.6%、活性度162mmol/100g、游离酸0.013%.采取正交实验优化一次提纯土制备活性白土的工艺,得最佳工艺条件为固液比为1:3、加酸量70%、活化时间为4h,得到产品的脱色枣99%,活性度135.6mmol/100g游离酸0.011%.