In this study, we employed a synergistic process combining alkaline leaching pretreatment with mixed acid leaching to purify quartz sand and efficiently eliminate metallic impurities. First, systematic single-factor optimization was used to determine the optimal alkaline leaching parameters to be a NaOH concentration of 8%, a reaction time of 2 h, and a temperature of 225 degrees C. After alkaline leaching, a porous and loose structure was formed on the quartz surface, along with a large number of cracks and pits, which significantly enhanced the mass transfer efficiency of the subsequent acid leaching. Based on this, a ternary mixed acid system (H3PO4-H2SO4-H2C2O4) was used for pressure leaching. The acid leaching process parameters were optimized using response surface methodology, which determined the optimal conditions to be a temperature of 249 degrees C, a solid-liquid ratio of 1:5, and a time of 6 h. After treating the quartz sand with the combined process, the sand's total metallic impurity content was significantly reduced from the initial 523.2 mg/kg to 82.6 mg/kg, which amounts to an overall removal rate of as high as 84.33%. The contents of Al, Ca, Fe, K, Mg, Na, and Ti were 50.4, 8.1, 2.2, 6.9, 2.3, 11.5, and 1.2 mg/kg, respectively.

To address the problem of low efficiency in activating peroxymonosulfate (PMS) by ordinary copper slag for degrading organic pollutants, doping modification is the key to improving its activity. In this study, an in-situ synthesis method was used to prepare a nitrogen-doped mesoporous material from waste copper slag (Fe-N1/8), which can effectively degrade Rhodamine B (RhB). Single-factor experiments showed that Fe-N1/8 exhibited excellent catalytic performance at a low PMS concentration (0.25 mM - 1 mM), achieving 100% degradation of RhB (50 mg/L) within 15 min. Stability tests revealed that Fe-N1/8 maintained its significant PMS activation effect, strong magnetism, excellent acid-base tolerance (pH = 3 - 11), and good anion interference resistance (Cl-, NO3-, H2PO4-, etc.) during three degradation cycles. Meanwhile, VSM tests indicated that Fe-Ni/e has strong magnetism, which is beneficial for the recovery and reuse of the catalyst. Free radical scavenging experiments and ROS identification analysis confirmed that in the Fe-N1/8/PMS system, there is a synergistic effect between non-radical pathways (1O2, electron transfer) and radicals (SO4-·, ·OH), along with an effective cycle of Fe(II) and Fe(III), among which 1O2 is the main active substance driving rapid degradation. LC-MS analysis identified the intermediate products during the degradation process, and the degradation pathways and mechanisms were proposed. Additionally, the toxicity of the intermediate products was analyzed using ECOSAR software and seed germination tests. This study successfully developed an environmentally friendly functional material using industrial solid waste, achieving the goal of "treating waste with waste" and providing a new perspective for the high-value utilization of copper slag and the purification of dye-containing wastewater.

This study reported an ecofriendly inorganic zinc composite coating for protecting marine steel based on alkali-activated technology, which coupled synergistically with the passivated effect of alkali-activated slag (AAS) and the cathodic protection of zinc dust. The coating was directly coated on carbon steel and exposed to simulated seawater to explore its protective properties. The effects of chemical compositions of AAS on the corrosion protection of steel and the chemical durability of the coating were investigated. Results showed that the zinc-based AAS coating had a passivated ability for steel with chemical bonding with steel by forming a C-A-S-H/C-S-H gel-like layer. Furthermore, the AAS coating guaranteed excellent barrier protection owing to its superior durability, and no obvious steel rust deposits were found after long-term exposure to the chloride solution. The concentration of NaOH influenced the protective properties of the passivated film due to the reducing effect of OH groups. The addition of nanosilica in the AAS formed a compacted coating structure, which was beneficial for the long-term passivation process of steel/zinc and improved the cathodic protection efficiency of zinc dust. The loss of alkaline species of the pore solution and degradation of the AAS structure were the main failure mechanisms of the coating during the chloride solution immersion. The optimal coating exhibited 3.8 MPa bonding strength, a cathodic protection period beyond 2800 h (2 times more than organic coating), and negligible degradation of the AAS coating binder. The AAS-based coating exhibited longer corrosion protection and advantages in durability and sustainability. This study provides new insight into designing sustainable anticorrosion coating for protecting steel in harsh marine environments.

In this paper, a multi-functional petal-like geopolymer/Mo2S3 composite membrane (PG/Mo2S3CM) was synthesized in situ through the hydrothermal method, with a porous geopolymer membrane (PGM), thiourea, and sodium molybdate as the raw materials. When the contents of thiourea and sodium molybdate were 4.14 g and 4.38 g respectively, the PG/Mo2S3CM demonstrated optimal performance in water treatment. The high degradation rate of Rhodamine B (RB) and the significant removal rate of Ni(II) exceeded 99 % and 92 % respectively. The PG/Mo2S3CM exhibits excellent continuous use performance, reusability performance, and environmental tolerance. Under one sun irradiation, the evaporation rate of the PG/Mo2S3CM reached 1.53 kg center dot m-2 center dot h-1 . The experimental results confirm the enhancing mechanisms of RB and Ni(II) removal. The increase in center dot OH, sulfur vacancies, and the synergistic effect between PGM and Mo2S3 are the reasons for the high performance of PG/ Mo2S3CM. The enhancing mechanisms of solar-driven evaporation on PG/Mo2S3CM involve the synergistic effect of the good water transfer rate of PGM and the excellent photothermal effect of molybdenum sulfide. This work offers a novel strategy for the development of a multifunctional geopolymer composite material for use in the field of water purification and recovery.

To address the dual challenges of coal gangue utilization and azo dye wastewater treatment, this study developed cobalt-loaded geopolymer microsphere catalysts (Co@CGM) through the resource utilization of coal gangue for peroxymonosulfate (PMS) activation, achieving efficient degradation of azo dyes sunset yellow (SY) and amaranth red (AR). Single-factor experiments demonstrated that Co@CGM exhibited exceptional catalytic performance at ultra-low PMS concentrations (0.25-0.50 mmol/L), achieving degradation efficiencies of 99.38% for SY and 99.91% for AR within 30 min for 100 mL solutions at 50 mg/L concentration. Stability tests revealed that Co@CGM maintained significant PMS activation effectiveness through five degradation cycles, demonstrating strong acid-base resistance (pH=3-9) and excellent anion interference resistance (Cl-, NO3-, H2PO4-, etc.). Quenching experiments and electron paramagnetic resonance spectrometer (EPR) analysis confirmed that singlet oxygen (1O2) served as the primary reactive species driving the rapid degradation process in both SY and AR systems. Liquid chromatography-mass spectrometer (LC-MS) analysis identified intermediate products and proposed degradation pathways for both dyes. This work successfully developed an eco-friendly functional material through coal gangue waste recycling, achieving the goal of "treating waste with waste" in azo dye wastewater remediation.

电解锰渣是电解锰生产过程中产生的固体废弃物,其中含有大量的Mn2+和NH3-N等有害物质.目前电解锰渣主要以露天堆放为主,对周围土壤及地下水存在极大污染隐患.研究首先介绍了电解锰渣的主要化学成分、矿物组成以及浸出毒性,综述了近年来电解锰渣在无害化及资源化利用方面的进展,包括固化稳定化,制备混凝土用掺合料、水泥、免烧砖等建筑材料以及沸石分子筛等功能材料,并对各处理方案的实施效果及存在的问题进行了讨论.

随着信息化时代的到来,众多的制造行业通过步入智能化改造升级行列解决行业内出现的高物耗、高能耗、高污染的问题,朝着绿色可持续的方向发展.针对广西特色资源锰加工行业的问题,靖西市大西南锰业有限公司开展电解锰智能化技术改造,率先实现了智能化生产,大幅度降低了人力、能耗等成本,明显提升了企业的经济效益,对电解锰行业智能化转型升级具有重要的借鉴意义.

磷酸盐胶凝材料力学性能好,制备工艺简单,为资源化利用铜渣提供了新的途径.本文以铜渣和磷酸二氢钠(NaH2 PO4)为原料制备了磷酸盐胶凝材料,采用电子万能试验机、X射线粉末衍射仪及扫描电子显微镜研究了原料配合比和养护条件对铜渣基磷酸盐胶凝材料抗压强度、物相和微观形貌的影响,并采用同步热分析仪考察了磷酸盐胶凝材料的热稳定性.结果表明,原料配合比对磷酸盐胶凝材料的力学性能和微观结构有重要影响,适当提高养护温度有利于强度发展.当NaH2PO4/铜渣质量比为0.30、水/(NaH2PO4+铜渣)质量比为0.15、60℃下养护7 d时,铜渣基磷酸盐胶凝材料抗压强度高达54.70 MPa.铜渣基磷酸盐胶凝材料优异的力学性能源自铜渣中铁橄榄石(Fe2 SiO4)与NaH2 PO4反应生成的致密无定形结构相.铜渣基磷酸盐胶凝材料热稳定性较好,空气气氛下467℃开始被氧化分解,无定形结构相发生相转变.

工程教育专业认证理念对高等院校的高质量发展,尤其是对大学生未来就业有着重要的意义.民族院校的学生由于生源等原因,加上化工原理实验课程教学存在的问题,工科类专业课程教学如何结合工程教育专业认证理念和自身实际情况改进教学,跟上时代的步伐,是许多教育工作者需要考虑的问题.文章对开展工程教育专业认证的重要性,化工原理实验课程教学的意义、存在的问题、教学改革现状和探索进行了阐述.

以活性炭和偏高岭土为原料、水玻璃和氢氧化钠为激发剂,采用悬浮固化法制备了活性炭/地质聚合物复合微球(GMC)吸附剂,通过X射线衍射仪、扫描电镜和紫外-可见分光光度计研究了其微观结构以及对刚果红(CR)和结晶紫(CV)的吸附性能.结果表明,GMC的吸附性能随活性炭添加量增加而提高,活性炭添加量为30％时,其对CR和CV的吸附过程符合Langmuir吸附模型和准二级动力学模型,理论最大吸附量分别为61.88 mg/g和104.06 mg/g,循环再生使用5次后对CR和CV的去除率依然可达71.73％和75.65％.

以活性炭、煅烧高岭土和工业水玻璃为主要原料,在油相中悬浮分散制备活性炭-地聚物复合微球(CGM)吸附剂.通过XRD和SEM对其结构进行了表征,重点研究了 CGM对罗丹明B(RB)和亚甲基蓝(MB)的吸附过程.结果表明:CGM对RB和MB的吸附更接近准二级动力学模型,等温吸附过程都能用Langmuir和Freundlich方程较好的拟合,298 K时吸附剂对RB和MB的理论最大吸附容量分别为34.96、52.77 mg/g.

A novel strategy for hydrophobic modification of alkali-activated slag (AAS) by compositing potassium methyl silicate (PMS) to produce a protective coating for reinforced concrete was reported. Results show that PMS had an assisted-alkali activation, and could graft hydrophobic groups (-CH3) on the C-A-S-H/C-S-H gel chemical structure by condensation reaction. While PMS had a retard effect and reduced mechanical property due to the decreased binding energy of atoms and condensation degree of gel. The coating with 5 wt.% PMS obtained a compacted microstructure, where gel production increased 26%, porosity decreased 54%, and harmless pore volume improved 14%. The fabricated coating had excellent protective properties, which showed a bonding strength of 1.60 MPa, water contact angle of 128°, water absorption of 2.8%, chloride ion penetration coefficient of 5.453×10-12 m-2/s, and the corrosion rate of reinforced rebar decreased by 97%.

Electrolytic manganese dioxide residue (EMDR) is a type of industrial solid waste that contains many soluble heavy metal ions. To reduce the hazard to environment, EMDR was proposed as raw material to fabricate phosphoric-acid-activated geopolymers in the present work. Relevant characteristics of these materials such as the compressive strength, bulk density, crystalline components, microstructure, leaching characteristic, high temperature resistance and corrosion resistance were investigated in this work. The results showed that EMDR was highly reactive with phosphoric acid and could be cured to form geopolymer gel materials with compressive strength up to 96.3 MPa after curing for 2 days at 80 degrees C with river sand added as an aggregate. Based on the analysis of X-ray diffraction and microstructure, the high compressive strength was due to the amorphous reaction products of phosphoric acid and magnetite in EMDR. The results of the leaching test of the geopolymer samples from EMDR showed that the manganese stabilization efficiency was 95.4%, and other measured elemental concentrations were all within the limits of Integrated Wastewater Discharge Standard in China when the CaO to wet EMDR ratio was 0.10. In addition, the geopolymers from EMDR showed good resistance to high temperature and aggressive environment except strong acid. Therefore, the results obtained in this study reveal that this method for the fabrication of geopolymers is a promising way to recycle EMDR and other iron-rich industrial solid wastes. (C) 2018 Elsevier Ltd. All rights reserved.

Spinel LiMn2O4 samples were prepared from electrolytic manganese dioxide (type P), electrolytic manganese dioxide with low sodium content and high purity Mn3O4 respectively. The properties and structure of the manganese sources and the LiMn2O4 products were determined by ICP, laser scattering particle size distribution analyzer, surface area analyzer, X-ray diffraction and scanning electron microscope. Electrical properties of the LiMn2O4 products were also studied by electrochemical measurements. The results show that the reaction activity of electrolytic manganese dioxide with low sodium content and high purity Mn3O4 was higher than electrolytic manganese dioxide (type P). The LiMn2O4 prepared by electrolytic manganese dioxide with low sodium content and high purity Mn3O4 had better cycle behavior at 55 °C with the capacity retention of 78.2% at the 400th cycle.

Combining with the actual situation of chemical enter-prises in southwest Guangxi and chemical professional talent training in our university, university-enterprise cooperation pat-tern was established. Through investigationg local enterprises practice teaching base was established;the talent training scheme was revised unitedly; enterprise engineering and technical per-sonnel was employed to teach on campus. Course practice, cog-nition practice, graduation practice and graduation thesis (design) were completed with the enterprise; chemical professional stu-dents' practical knowledge and comprehensive ability were pro-moted;the construction of"double-type"teachers was strength-ened;and applied talents were cultivated together with the enter-prise.

尖晶石型锰酸锂是非常有发展前景的锂电正极材料,叙述了改善尖晶石型锰酸锂电化学性能及加工性能的方法,包括优化其粒度分布、降低杂质含量、控制一次晶粒及整体颗粒形貌、元素掺杂、表面改性以及制备方法优化等.

研究了不同富锂量对锰酸锂性能的影响.对合成的材料进行了XRD、SEM、全电池充放电测试.结果表明,在热处理温度为920℃时,合成材料均为尖晶石相,随着富锂量的增加,颗粒的一次粒子粗化明显,比容量减小,倍率性能和循环性能提高;当富锂量为0.20 mol时,样品综合电化学性能最佳,1C放电比容量为90.4 mA·h/g,25℃和55℃下的1C充放50次,循环保持率分别为97.9％和94.1％.

The phase,morphology and specific surface area of MnO2 calcinated at 850℃ for 10 h,was studied here.And spinel LiMn2O4 was synthesized by high temperature reaction with calcinated MnO2 and uncalcinated MnO2 respectively.The difference of the two kinds of LiMn2O4 on phase,morphology,specific surface area and electrochemical performance was investigated.The results show that the calcinated MnO2 is porous Mn2O3 with specific surface area 1.250 m2/g.Compared to the LiMn2O4 synthesized with uncalcinated MnO2,the crystal grain of the LiMn2O4 with calcinated MnO2 is larger and more uniform,and it has smaller specific surface area(0.677 m2/g) and better cycle performance.Its capacity maintains 97.11% after 50 cycles with 1 C rate at 25℃.

The experimental research is to press the lithium manganate mixture into clumps before sintering,then the clumps are put in the furnace for sintering.Because the bulk density of the mixture increases from 1.06 to 1.39 in thickness of the compacted matter,a sagger of the same volume can fill 31% more,that is to say,under the same power consumption and working hours with the traditional process,the production of lithium manganate can increase by 31%.At the same time,this method can improve the hyperthermia solid-state reaction dynamic condition,by helping the growth of reaction product grains and perfection of crustal form to improve the quality of lithium manganate products with an increase the compacted density from about 2.90 to above 3.00.The result is the volume energy density of the battery will be increased.

The effects of particle size distribution on compacted density of LMO material was researched in order to improve the size distribition of LMO.Results indicated that the material had the highest compacted density of 3.14 g/cm3 at a concentrated particle size distribution such as D10=6.330 μm,D50=11.431 μm,D90=19.424 μm and D90-D10=13.094 μm.The full cell 1C made from the material had an initial discharge capacity of 105.3 mAh/g and capacity attenuation rate after 50 cycles of 4.26%.This material can meet with the requirements of a lithium battery plant.