从核电站废液中回收硼酸

随着现代科技的进步,世界范围内对高丰度10B的需求越来越大,尤其是核电站反应堆中需要大量的富集硼-10酸,而目前我国使用的富集硼-10酸完全依靠进口,从而限制了我国高新技术的发展.文中介绍了硼酸在核电站中的作用以及从核废液中回收硼酸的重要意义.结合液-液萃取﹑离子交换吸附﹑膜分离和蒸发4种分离技术的原理,以及这4种分离...     

异辛醇-甲苯萃取盐湖卤水中硼酸的动力学

引言硼及其化合物在国民经济中用途极为广泛[1],但是我国主要的硼原料之一硼镁矿石却日趋枯竭,于是开发液体硼矿资源--含硼盐湖卤水成为当务之急.近年来杨卉芃等[2]、李文强[3]、杨存道等[4]分别以沉淀法、离子交换法和结晶法对盐湖卤水提硼工艺进行了研究,并取得了一定的成果.     

Recovery of boric acid from ulexite by leaching with hydrochloric acid derived from waste chlorine gas and froth flotation

A process for producing boric acid from ulexite and the recovery of the product by flotation is described. It was found that the degree of conversion of ulexite to boric acid decreased with rising HCl concentration. The undissolved mineral, together with other impurities such as clays, could be depressed by Quebracho, Orzan-S, Daxad-23 or starch, the first two being more effective. Concentrates assaying 97.1% H₃BO₃ were obtained without resorting to recrystallisation of the product. No flotation reagents other than the above-mentioned were necessary for the process.     

Recovery of boric acid from ulexite by leaching with hydrochloric acid derived from waste chlorine gas and froth flotation

A process for producing boric acid from ulexite and the recovery of the product by flotation is described. It was found that the degree of conversion of ulexite to boric acid decreased with rising HCl concentration. The undissolved mineral, together with other impurities such as clays, could be depressed by Quebracho, Orzan-S, Daxad-23 or starch, the first two being more effective. Concentrates assaying 97.1% H₃BO₃ were obtained without resorting to recrystallisation of the product. No flotation reagents other than the above-mentioned were necessary for the process.     

氢氟酸生产废酸制氟硼酸钾工艺研究

为充分利用氢氟酸生产过程中副产废酸中12％（质量分数）的有效氢氟酸，对其代替工业氢氟酸（质量分数30％）生产氟硼酸钾的可行性进行了分析、研究、探讨。经过试验证明先用化学计量的硼酸与30％（质量分数）氢氧化钾反应制成偏硼酸钾溶液，偏硼酸钾溶液再与废酸反应制得氟硼酸钾的工艺是完全可行的，实施后每年可回收氢氟酸120t（以100％计），具有很大的经济效益。     

氟硅酸、硼酸制备氟硼酸钾工艺研究

详细介绍了利用磷肥副产的氟硅酸和硼酸反应生产高附加值的氟硼酸钾的工艺方法。通过对工艺的研究,叙述了该工艺的反应原理、工艺流程、工艺控制、主要设备及设备的优越性。通过实验表明,利用氟硅酸中的氟与硼酸反应生产氟硼酸和白炭黑,氟硼酸与氯化钾反应生成氟硼酸钾的方法可行。氟、硼反应温度在75～85 ℃、时间为2.5～3 h转化率较高,氯化钾需按理论量加入,产品质量稳定。该工艺利用磷肥行业副产的氟硅酸制备氟硼酸钾,将氟硅酸中的氟转化为氟硼酸钾,硅转化为白炭黑,不仅实现了资源综合利用,而且将生产废弃物转化为新的产品创造了新的利润增长点,节约了化石资源萤石,同时较氢氟酸法成本有大幅度下降,该方法将会成为未来氟硼酸钾生产的发展趋势。     

Impurity control in the production of boric acid from colemanite in the presence of propionic acid

The most important problem in boric acid production from colemanite ores with H₂SO₄ is the formation of MgSO₄ impurity due to the partial decomposition of clay minerals in the reaction media. Increase of MgSO₄ concentration in solution may be balanced by the discharge of mother liquor which leads to decrease the efficiency of the process. Therefore, the intake rate of MgSO₄ should be lowered for obtaining high purity product in a high yield process. In order to control the intake rate of MgSO₄ impurity, propionic acid, which does not decompose the clay minerals, is used in an acid mixture with H₂SO₄. Batch wise laboratory experiments showed that the higher the propionic acid in reacting acid mixture, the lower the magnesium intake rate. When 10% of required H₂SO₄ replaced by propionic acid, magnesium intake concentration decreased to approximately half of the value obtained in the reaction with H₂SO₄.     

硼酸在无碱玻璃纤维生产上的应用

1 引言 在无碱玻璃纤维生产中,氧化硼(B_2O_3)是玻璃中的一种重要组分,它能降低玻璃液的熔制温度、调整玻璃液的粘度和表面张力,防止断丝。氧化硼还可加强原丝的抗水性和抗化学性,加强玻璃纤维与树脂的粘附能力。     

Design parameters of boric acid production process from colemanite ore in the presence of propionic acid

In this study, three different boric acid production process alternatives which can be performed in the presence of propionic acid and/or calcium propionate were evaluated. The process in which calcium propionate is the recycling component was selected as the best alternative and modeled. Some of the design parameters were determined for the selected process. These parameters are solubility change of boric acid in the presence of calcium propionate at 25 °C, 35 °C and 75 °C, precipitation risk of calcium borate components in concentrated boric acid solutions containing calcium propionate, and the effect of calcium propionate on the solution pH with respect to free sulfuric acid concentration. According to the determined parameters, principal reactions occurred in the process, and other process parameters obtained by industrial practice, mass balances were conducted and all flow rates were calculated. In the process, calcium propionate concentration in production liquor must be kept lower than 3% and the reaction must be carried out without any free sulfuric acid in order to perform the process according to the model.     

Kinetics of the thermal degradation of wax materials obtained from pyrolysis of mixed waste plastics

We did a kinetic analysis of the thermal degradation of wax materials obtained from pyrolysis of mixed waste plastics using the nonisothermal weight loss technique with heating rates of 10, 20, 30 and 40 °C/min. The weight loss data according to degradation temperature were analyzed by using the integral method based on Arrhenius form to obtain the kinetic parameters. To verify the effectiveness of the proposed kinetic analysis method, the experimental values were compared with those of the numerical integration results using kinetic parameters obtained in this work. It was found that the proposed kinetic analysis method gave reliable kinetic parameters of the thermal degradation of wax materials obtained from pyrolysis of mixed waste plastics.     

离子交换法从卤水中提取硼酸

中国很多的盐湖卤水中都富含大量的硼矿资源，从中提取硼酸的方法也有很多，如：酸化结晶法、沉淀法、萃取法、离子交换法等，其中离子交换法被认为是这些方法中最有前途的方法之一。综述了采用离子交换法从含硼盐湖卤水中提取硼酸的工艺原理和影响因素，列出了几种常用的提硼树脂，介绍了应用离子交换法从卤水中提取硼酸的现状。     

Formation,microstructure and properties of aluminum borate ceramics obtained from alumina and boric acid

The formation of aluminum borates (Al₁₈B₄O₃₃ and Al₄B₂O₉) from alumina and boron oxide occurs between 600 and 800 °C. These materials have refractory properties and corrosion resistance. The objective of this work is to develop materials from the Al₂O₃-B₂O₃ system, employing alumina and boric acid as starting powders, to study the critical processing variables and describe the developed microstructure and properties.Three formulations (13, 19.5 and 26 wt% B₂O₃) were studied. In order to confirm the formation of borates, the differential thermal analysis and thermogravimetric analysis were carried out. Afterwards, uniaxially pressed disc-shaped specimens were fired at four temperatures above the formation temperature. The textural properties of the ceramics were evaluated by the immersion method, this permit to evaluate the sintering processes. Then the degree of borate formation was confirmed by X-ray diffraction.Finally, the developed microstructures were characterized by scanning electron microscopy, and the diametral compression behavior was evaluated.A series of porous (≈50%) refractory materials from the Al₂O₃-B₂O₃ system were developed. The processing strategy resulted in materials with Al₁₈B₄O₃₃ as the main crystalline phase. Needle grains with diameters between 0.2 and 1 µm and an aspect ratio over 20:1 were obtained. Thus, based on the information gathered from our research, aluminum borate ceramic materials can be designed for structural, insulating or filtering applications employing only alumina and boric acid as boron oxide source.     

采用钠硼解石生产硼酸的工艺研究

由青海大柴旦钠硼解石矿中提取硼酸，找出了最佳工艺条件，即：矿粒细度〈1．7mm，反应温度80～90℃，反应液酸度（pH）2～3，结晶温度20～25℃，反应液中硼酸质量分数15％～16％，蒸发过程镁离子质量分数〈4％，渣带失（以三氧化二硼计）质量分数〈2％。在此条件下对其工艺技术的稳定性、可靠性及适应性进行了研究。结果表明，硼的总收率达85％以上，利用本地资源生产硼酸，投资少，见效快。     

硫酸法生产硼酸母液回收利用技术

介绍了提高硼酸收率、解决母液回收利用问题的方法，并对硫酸法生产硼酸母液回收利用进行了介绍，该工艺采用母液蒸发浓缩－冷却结晶－浮选分离的方法，达到精制硫酸镁、回收硼酸的目的，避免了资源浪费及环境污染，成品硼酸的质量不受影响，副产品七水硫酸镁的质量达到部标各项指标要求，没有环境污染，且已用于工业化生产。     

The sorption of ions by polyamides

An analysis is given of the principal thermodynamic factors that influence the distribution of an ion between a macroscopically homogeneous polymer phase and a second homogeneous phase and a general method is proposed for the computation of the equilibrium ion sorptions in well-defined model systems. Particular attention is paid to the sorption of ions by polymers containing ionizable groups and the method is used to clarify some of the current problems in the theoretical explanation of the mechanism of sorption of acid dye anions by polyamide fibers. The method is applicable in principle to any dyeing system in which the fiber phase may be regarded at equilibrium as a macroscopically homogeneous, equipotential volume.     

Kinetics and thermodynamics of glucoamylase inhibition by lactate during fermentable sugar production from food waste

BACKGROUND: Glucoamylase hydrolysis is a key step in the bioconversion of food waste with complicated composition. This work investigated the effect of lactate on glucoamylase from Aspergillus niger UV‐60, and inhibition mechanisms of glucoamylase by lactate during food waste hydrolysis. RESULTS: For 125 min hydrolysis of food waste (10%, dry basis), reducing sugars produced in the absence of lactate were 15%, 26% and 56% more than those produced in the presence of 24 g L^?1 lactate at 60, 50 and 40 °C, respectively. Kinetic study showed that the type of glucoamylase inhibition by lactate was competitive, and K_m (Michaelis‐Menten constent), V_max (maximum initial velocity), K_I (inhibition constant) were 103.2 g L^?1, 5.0 g L^?1 min^?1, 100.6 g L^?1, respectively, for food waste hydrolysis at 60 °C and pH 4.6. Lactate also accelerated glucoamylase denaturation significantly. Activation energy of denaturation without inhibitor was 61% greater than that of denaturation with inhibitor (24 g L^?1 lactate). Half‐lives (t_1/2) without inhibitor were 7.6, 2.7, 2.6, 1.7 and 1.2 times longer than those with inhibitor at temperature 40, 45, 50, 55 and 60 °C, respectively. CONCLUSION: These results are helpful to process optimization of saccharification and bioconversion of food waste. Copyright © 2010 Society of Chemical Industry     

Use of limestone obtained from waste of the mussel cannery industry for the production of mortars

Various types of cement−SiO₂−CaCO₃ mortar were prepared by replacing quarry limestone aggregate with limestone obtained as a by-product from waste of the mussel cannery industry. The CaCO₃ aggregate consists mainly of elongated prismatic particles less than 4 μm long rather than of the rounded particles of smaller size (2-6 μm) obtained with quarry limestone. The mechanical and structural properties of the mortars were found to be influenced by aggregate morphology. Setting of the different types of mortar after variable curing times was evaluated by scanning electron microscopy (SEM), thermogravimetric analysis (TG) and mercury intrusion porosimetry (MIP) techniques. Mortars with a high content in mussel shell limestone exhibited a more packed microstructure, which facilitates setting of cement and results in improved mortar strength. The enhanced mechanical properties of the new mortars allow the cement content in the final mortar composition to be decreased and production costs to be reduced as a result.     

萃取法分离钛白废酸中的铁

首先通过臭氧氧化作用把钛白废酸中的二价铁转化成三价铁,然后采用萃取法去除其中的三价铁。考察了络合剂（盐酸）浓度、萃取剂、萃取相比等对三价铁萃取率的影响,并初步探索了反萃法回收萃取剂及萃取剂的循环利用。结果表明：当盐酸浓度为3.4 mol/L时,几乎可完全络合溶液中的三价铁;在萃取剂磷酸三丁酯中加入苯作为稀释剂,可有效降低磷酸三丁酯的粘度,消除萃取过程中的乳化现象;磷酸三丁酯萃取三价铁的传质过程很快,2-3 min即达平衡;当萃取相比O/W（萃取剂与钛白废酸体积之比）=0.6∶1时,三价铁萃取率可达97%以上。当反萃相比W/O=4∶1时,三价铁反萃率接近100%。磷酸三丁酯经过5次萃取-反萃循环后,三价铁的萃取率没有明显下降。去除三价铁后的钛白废酸,经蒸馏浓缩到质量分数70%左右,再与浓硫酸混合后可用于钛白粉的生产,蒸馏过程中回收的盐酸循环使用。反萃出来的三价铁可作为生产铁红的原料。