磷酸法生产活性炭的探索

本文通过理论分析和生产实践，对磷酸法和氯化锌法生产活性炭进行对比，阐明磷酸法可替代污染严重的氯化锌法之可能性和必要性，为推广磷酸法生产提供依据，并提出研究方向。     

磷酸法生产活性炭的探索

本文通过理论分析和生产实践，对磷酸法和氯化锌法生产活性炭进行对比，阐明磷酸法可替代污染严重的氯化锌法之可能性和必要性，为推广磷酸法生产提供依据，并提出研究方向。     

磷酸法生产活性炭降低产品灰分的探讨

磷酸法生产活性炭降低产品灰分的关键措施是处理回收液，提高回收液的纯净度。     

改良活性炭回收湿法磷酸中的碘

在硫酸分解磷矿生产湿法磷酸的过程中,碘一般是以碘化物的形式进入湿法磷酸中。在湿法磷酸生产过程中,回收碘就显得十分重要,这既提高了磷矿资源的利用程度,符合可持续发展的要求,又为相关企业增加一种极有价值的产品,从长远看,将带来更多的收益。     

用磷酸法生产木屑活性炭

介绍江西省新岗山活性炭厂用磷酸法制取木屑活性炭，已形成规模化生产，解决了灰分问题和磷酸消耗问题。     

磷酸法木质活性炭的研究现状

对磷酸法木质活性炭的研究状况进行了综述,说明了磷酸浓度和加热条件对活性炭孔隙分布的影响,不同原料制备活性炭适宜的工艺条件。阐述了磷酸法活化的机理,指出了磷酸法灰分形成机理研究的重要性。     

磷酸法蔗渣制备活性炭研究

以甘蔗糖厂废弃的蔗渣为活性碳的生产原料,以磷酸作为活化剂生产活性炭,探索了生产活性炭的工艺条件。结果显示,最佳工艺条件为：陈化时间9 h、炭化温度300℃、炭化时间120min、活化温度400℃。活性炭的焦糖脱色率、亚甲基蓝吸附值两项指标均达到一级品的要求。     

Influence of chelating agents on the tribocorrosion of tungsten in sulphuric acid solution

The corrosion and tribocorrosion of tungsten in 0.01 M H₂SO₄, without and with the presence of lactic acid and phosphoric acid as chelating agents was studied here.The passive behaviour was characterised using potentiostatic polarization and potential step techniques combined with rotating disk electrodes. Surface analysis techniques (XPS, AES) were used to assess surface chemistry. The tribocorrosion of tungsten was investigated using a tribometer equipped with an electrochemical cell operating at applied passive potentials of 0.2 V and 1.0 V.Under static corrosion conditions chelating agents were found to enhance passive film dissolution and to decrease the passive film thickness. Despite this, the effect of the investigated chelating agents was limited under tribocorrosion conditions. Indeed, only lactic acid at the most anodic potential lead to significant differences in material removal by impeding the formation of protective tungsten oxide tribolayers. The discrepancy on the effect of chelating agents in corrosion and tribocorrosion was explained in terms of the different involved time constants.     

HEMP-derived activated carbon fibers by chemical activation with phosphoric acid

Activated carbon fibers were prepared by chemical activation of hemp fibers with phosphoric acid at different carbonization temperatures and impregnation ratios. Surface properties of the activated carbons fibers were significantly influenced by the activation temperature and the impregnation ratio. An increase of either of these parameters produced a high development of the porous structure of the fibers. Activated carbon fibers with apparent surface area of 1350 m²/g and mesopore volume of 1.25 cm³/g were obtained at 550 °C with an impregnation ratio of 3. The activated carbon fibers presented a high oxidation resistance, due to the presence of phosphorus compounds on the carbon surface. The oxidation resistance results suggest that C-O-PO₃ and mainly C-PO₃ and C-P groups act as a physical barrier, blocking the active carbon sites for the oxidation reaction.     

湿法磷酸净化生产工业磷酸新工艺的研究

采用湿法磷酸与盐酸法磷酸按体积比(1~6)∶1混合,除去Ca2+、SO42-、Fe3+等杂质,澄清过滤后的磷酸再用磷酸三丁酯进行6~12级萃取提纯浓缩以生产工业磷酸。该法利用盐酸萃取磷酸可大大提高中低品位磷矿的利用率,与湿法磷酸混配省去了传统脱硫、除铁工序,可节约成本,所得产品纯度高于工业磷酸行业标准。     

硫化氢在磷酸溶液中溶解度的实验研究

在用过量的五硫化二磷净化磷酸的工艺中,为确定五硫化二磷的最佳投加量和净化的工艺条件,采用气相单循环法,测定了常压下不同温度和不同硫化氢分压下硫化氢气体在磷酸溶液中的溶解度数据。结果表明,在实验范围内,硫化氢的溶解度随温度的升高和磷酸浓度的增加而降低,随硫化氢分压的增加而增加,且呈线性关系,符合一般气体的溶解度规律。用I.H.Cho模型对溶解度数据进行了关联和计算,关联式的显著性水平达0.01,实验值与理论值的平均偏差为1.60%。该结果对磷酸的净化工艺有一定的指导意义。     

磷酸活化炭气凝胶微球的电化学性能研究

以磷酸为活化剂,对炭气凝胶微球在高温下进行活化改性,并用活化产品制作超级电容器的电极。采用扫描电镜、N2物理吸附-脱附等对炭气凝胶微球的形貌结构进行表征,采用循环伏安、恒流充放电、交流阻抗等测定了材料的电化学性能。结果表明,磷酸活化效果温和,不会破坏炭气凝胶微球典型的圆球状外观和三维纳米孔隙结构。经过磷酸活化,炭气凝胶微球的电化学性能得到有效改善,材料的内阻降低,同时比电容提高将近一倍,最高可达184 F/g。     

活性炭脱除湿法磷酸色素的研究

在采用溶剂萃取法净化湿法磷酸时,磷酸中的有色杂质会与萃取剂作用,干扰萃取过程,因此有必要事先对磷酸进行脱色处理.对4种活性炭的脱色及再生性能进行了研究,用间歇实验筛选出了一种脱色性能好、磷损失小的活性炭.并用玻璃吸附柱进行连续吸附实验,测定了其初始脱色率和最佳用量,以及经过1次再生和2次再生的再生率和最大脱色率.实验结果表明,新炭的最佳用量为1 kg原酸用12.9 g新炭,脱色率为72%;1次再生的活性炭再生率为99.5%,脱色率达到新炭的95%.适用于湿法磷酸脱色的活性炭是颗粒状、比表面积大、孔隙体积大和平均孔径大的一类产品.     

离子筛在湿法磷酸净化工艺中的应用研究

合成了一种用于湿法磷酸净化的离子筛，实验表明该离子筛可在强酸性介质中很好地工作，连续运行未见吸附效果受影响，结合磷矿石预处理、浸出液预处理及离子筛吸附，有望获得较为优化的湿法磷酸净化工艺。     

磷酸活化烟草杆制备中孔活性炭的研究

以烟草杆为原料,以磷酸为活化剂,采用一步炭化法制备了活性炭。采用正交实验研究了磷酸质量分数、浸渍时间、炭化温度及保温时间对活性炭得率和吸附性能的影响,在最佳工艺条件(磷酸质量分数30%,浸渍时间48 h,炭化温度750℃,保温时间20 min)下,所制备的活性炭其碘吸附值为889.36 mg/g,亚甲基蓝吸附值为21.5 mL/(0.1 g),得率为36.90%。同时测定了该活性炭的液氮吸附等温线,并通过BET、H K方程、D A方程和密度函数理论(DFT)表征了活性炭的孔结构。结果表明,该活性炭为中孔型,BET比表面积为892 m2/g,总孔体积为0.467 8 mL/g,微孔占总孔体积的37.06%,中孔占62.85%,大孔占0.07%。最后采用电子探针和透射电镜分析了活性炭的微观结构,其结构与氮吸附测定的结果较为一致。     

中国热法磷酸生产现状概述

介绍中国热法磷酸生产现状,总结热法磷酸生产经验,提出设备设计原则,设备制作安装技术要求以及生产操作注意事项。     

Removal of phenol and phosphoric acid from wastewater by microfiltration carbon membranes

Microfiltration carbon membranes were developed to cope with the wastewater containing phenol and phosphoric acid. The structure of carbon membranes was characterized by scanning electron microscope, x-ray diffraction, bubble pressure method and specific surface area analysis. The separation efficiency of carbon membranes was investigated by varying the operation factors, including feed concentration, running time, and pressure. Results have shown that the carbon membranes are abundant in porous structure with the porosity of 42%, along with a narrow pore size distribution centering at 0.18?µm. Within the scope of the study, the highest removal rates reach to 81.9% for phenol and 55.3% for phosphoric acid from wastewater, respectively.