Hydroxycitric acid ameliorates inflammation and oxidative stress in mouse models of multiple sclerosis

Hydroxycitric acid （HCA） is derived primarily from the Garcinia plant and is widely used for its anti-in- flammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund＇s Adjuvant （CFA） emulsion containing myelin oligodendrocyte glycoprotein （35-55）. Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reduc- tase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress.

Modulation of physical properties of oxide thin films by multiple fields

Recent studies of the modulation of physical properties in oxide thin films by multiple fields are reviewed.Some of the key issues and prospects of this area of study are also addressed.Oxide thin films exhibit versatile physical properties such as magnetism,ferroelectricity,piezoelectricity,metal–insulator transition（MIT）,multiferroicity,colossal magnetoresistivity,switchable resistivity.More importantly,the exhibited multifunctionality can be tuned by various external fields,which has enabled demonstration of novel electronic devices.

Synthesis and X-Ray Diffraction Study of All Rare-Earth Series Oxides REE_2Ti_2O_7

The pyrochlore supergroup natural minerals are the oxides for formula A2-xB2O7. In this formula, A typically is Ca, Na, TR, Ba, Fe and Mn cation. B is Ta, Ti, Nb, W, Sb. The pyrochlore supergroup is divided into five groups basis of the atomic proportions of the B-site atoms Nb, Ta, Sb, Ti, and W. They are pyrochlore, microlite, roméite, betafite, and elsmoreite, respectively. Some of these minerals containing rare-earth elements species or synthetic oxides have important applications in materials, as for optical materials, light catalyst materials, magnetoelectric materials and radioactive waste treatment etc.

High Performance Silicon Nitride-based Composite Materials with Rare-earth Oxides Additives

In the present paper,a silicon nitride-based composite processed with rare-earth oxidesadditives is presented.Its bend strength can be maintained at a value as high as 1000 MPafrom 1000 to 1370℃ and the fracture toughness measures 9-10 MPa·m1/2.The static fa-tigue behavior at 1370℃ of this material is also encouraging.Besides,two another α′/β′sialon composites doped with rare-earth oxides are also described.The effects of processingparameters on the microstructure and the properties of the materials are discussed in somedetails.

Evaluation of oxidative and nitrosative stress in relapsing remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS) through demyelination and neurodegeneration. Several lines of evidence support a role for oxidative and nitrative stress (OS and NS) in pathogenesis of multiple sclerosis. The mechanism of influence of OS and NS on blood-brainbarrier (BBB) has critical importance for evaluating antioxidant therapies. As far as we know, markers of oxidative and nitrative stress in MS patients have been investigated independently for their relationship with the state of the blood-brain-barrier. Blood plasma samples of 58 patients with relapse-remitting MS (RRMS) with normal (Group A, n = 48, 36.2 ± 10.5 years) and damaged BBB (Group B, n = 10, 38.2 ± 11.2 years) and of 44 healthy controls (39.2 ± 14.9 years) were analyzed. TAS (total antioxidant plasma status), lipoperoxides, protein carbonyls, 3-nitrotyrosine and uric acid were evaluated in each group. Our results confirmed decreased TAS (Group A: 1.35 ± 0.55 mmol/l, P e level of lipoperoxidation positively correlated with the state of BBB (P of protein’s carbonyls (A: 0.48 ± 0.11 nmol/mg protein, P nmol/l, P ed damage to plasma proteins, what was confirmed by their positive mutual correlation (P The level of uric acid was physiological and correlated negatively with protein’s carbonyls (P 0.05) while there was no significant relationship with 3-nitotyrosine. The results suggest the role of this antioxidant in the protection of the proteins against OS what was confirmed by its positive correlation with TAS

Separation and Manipulation of Rare-earth Oxide Particles by Dielectrophoresis

A challenge in chemical engineering is the separation and purification of rare-earth elements and their compounds. We report the design and manufacture of a dielectrophoresis(DEP) microchip of microelectrode arrays. This microchip device is constructed in order to use DEP to capture micro-particles of rare-earth oxides in petro-leum. Dielectrophoretic behavior of micro-particles of rare-earth oxides in oil media is explored. The dielectropho-retic effects of particles under different conditions are investigated. It is showed that the prepared microchip is suit-able for use in the investigation of dielectrophoretic responses of the rare-earth oxides in oil media. The factors such as frequency,particle size and valence of rare-earth metal are discussed. When the frequency is fixed,the transla-tion voltage decreases as particle size increases. Lower frequencies are more effective for manipulation of inorganic particles in oil media. Particles of the same rare-earth oxide with different size,as well as particles of different rare-earth oxides,are captured in different regions of the field by regulating DEP conditions. This may be a new method for separation and purification of particles of different rare-earth oxides,as well as classification of particles with different size.

Dynamic Thiol-Disulphide Homeostasis in Patients with Multiple Sclerosis

Objective: The aim of this study was to evaluate thiol-disulphide homeostasis in patients with Multiple Sclerosis (MS) during attack and remission. Design and Methods: A total of 82 patients admitted to our clinic were divided into 2 groups according to whether they are having an attack or not. Peripheral blood samples were taken from all patients and their native thiol, disulphide and total thiol concentrations were measured by a newly developed automated method. In addition, their disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were calculated. Results: The average disulphide values, disulphide/native thiol and disulphide/total thiol ratios of the patients with MS who were having an attack were found to be significantly higher compared to those in remission (p = 0.001, p = 0.001, p = 0.001, respectively). Conclusion: Our results have shown that thiol-disulphide balance was shifted to the oxidative area during the relapse. These homeostasis parameters, which can be easily measured by this newly developed method at low costs, may be important in terms of showing the disease activity and presenting the underlying mechanisms of the disease.

Effect of Sheng-jiang powder on multiple-organ inflammatory injury in acute pancreatitis in rats fed a high-fat diet

BACKGROUND Obesity worsens inflammatory organ injury in acute pancreatitis(AP), but there is no effective preventive strategy. Sheng-jiang powder(SJP) has been shown to alleviate multiple-organ inflammatory injury in rats with high-fat diet-induced obesity. Hence, SJP is supposed to have an effect on multiple-organ inflammatory injury in AP in rats fed a high-fat diet.AIM To explore how obesity may contribute to aggravating inflammatory organ injury in AP in rats and observe the effect of SJP on multiple-organ inflammatory injury in AP in rats fed a high-fat diet.METHODS Rats were randomly assigned to a control group(CG), an obese group(OG), and an SJP treatment group(SG), with eight rats per group. The rats in the OG and SG were fed a high-fat diet. From the third week, the rats in the SG were given oral doses of SJP(5 g/kg of body weight). After 12 wk, AP was induced in the three groups. Serum amylase level, body weight, Lee's index, serum biochemistry parameters, and serum inflammatory cytokine and tissue cytokine levels were assessed, and the tissue histopathological scores were evaluated and compared.RESULTS Compared with the CG, serum triglyceride, total cholesterol, interleukin-6, and interleukin-10 levels were significantly higher in the OG, and serum high-density lipoprotein cholesterol level was significantly lower in the OG. Moreover,enhanced oxidative damage was observed in the pancreas, heart, spleen, lung,intestine, liver, and kidney. Evidence of an imbalanced antioxidant defense system, especially in the pancreas, spleen, and intestine, was observed in the obese AP rats. Compared with the OG, serum high-density lipoprotein cholesterol, interleukin-10, and superoxide dismutase expression levels in the pancreas, spleen, and intestine were increased in the SG. Additionally, SJP intervention led to a decrease in the following parameters: body weight; Lee's index; serum triglyceride levels; serum total cholesterol levels; malondialdehyde expression levels in the pancreas, heart, spleen, lung, and liver; myeloperoxidase expression levels in the lung; and pathological scores in the liver.CONCLUSION Obesity may aggravate the inflammatory reaction and pathological multipleorgan injury in AP rats, and SJP may alleviate multiple-organ inflammatory injury in AP in rats fed a high-fat diet.

人参皂苷Rg1治疗多发性骨髓瘤的网络药理学预测与验证

目的:利用网络药理学和体外细胞实验,探究人参皂苷Rg1治疗多发性骨髓瘤(MM)的作用机制。方法:利用TTD、DisGeNet、GeneCards、PharmGKB、PubChem、Super-PRED、PharmMapper预测MM靶标,利用CTD和SymMap数据库预测人参皂苷Rg1靶标,取交集靶点构建蛋白质-蛋白质相互作用网络。基于基因本体(GO)和KEGG-pathway数据库,富集Rg1治疗MM的主要生物功能和信号通路。分子对接验证核心靶点与Rg1之间的结合能力。利用CCK-8、流式细胞术、Western blot实验,分别检测不同剂量人参皂苷Rg1(5、10、20μmol/L)对RPMI 8226细胞的细胞活性、凋亡率、ROS水平及核心作用靶点Caspase3、Bax、Bcl-2、和NF-κB p65的相对表达。结果:筛选得到215个Rg1-MM靶点。GO和KEGG富集分析提示Rg1改善MM的作用机制可能涉及氧化应激、细胞凋亡及炎症相关信号通路。分子对接提示Rg1可能通过调控NFKB1、STAT3、AKT1、MAPK3、CASP3、BCL2等靶点发挥效用。体外实验表明,与对照组比较,Rg1组(5、10、20μmol/L)可显著抑制RPMI 8226细胞增殖(P<0.01)、促进细胞凋亡(P<0.01)和ROS产生(P<0.01),同时抑制NF-κB信号通路的活化(P<0.05)。结论:人参皂苷Rg1对MM有潜在的治疗作用,能够调节RPMI 8226细胞的氧化应激、细胞凋亡和增殖,其作用机制涉及对NF-κB信号通路的调控。

多发伤患者早期肠道菌群及其代谢产物氧化三甲胺的变化

目的:多发伤患者一旦并发脓毒症和多器官功能障碍综合征则预后不良。本研究通过观察多发伤患者早期肠道菌群及其代谢产物氧化三甲胺的变化,探讨多发伤患者并发脓毒症和多器官功能障碍综合征的可能机制。方法:选取2023年4月至9月江苏大学附属医院收治的符合纳入标准的多发伤患者25例作为多发伤组,选取同期本院体检中心符合纳入标准的健康志愿者25例作为对照组。收集多发伤组伤后1周左右的粪便标本和血浆标本,同期收集对照组体检当天的粪便标本和血浆标本。通过16S rRNA高通量测序技术检测粪便标本,分析多发伤组和对照组肠道菌群的差异。采用高效液相色谱-质谱串联技术检测血浆标本,分析多发伤组和对照组血浆氧化三甲胺水平的差异。结果:多发伤组和对照组的肠道菌群构成存在明显差异。在菌门水平上,多发伤组变形菌门的相对丰度明显高于对照组(P<0.05);厚壁菌门和拟杆菌门的相对丰度明显低于对照组(P<0.05)。在菌属水平上,多发伤组大肠埃希菌属、致病肠球菌属、梭菌属、考拉杆菌属的相对丰度均明显高于对照组(均P<0.05),普氏菌属、双歧杆菌属、瘤胃菌属、乳杆菌属、粪球菌属、布劳特菌属、丁酸弧菌属的相对丰度均明显低于对照组(均P<0.05)。多发伤组血浆氧化三甲胺水平明显高于对照组(P<0.05)。结论:与健康人群相比,多发伤患者早期肠道菌群已发生变化,专性厌氧菌相对丰度下降,兼性厌氧菌相对丰度上升,有益共生菌相对丰度减少,机会致病菌相对丰度增加,这可能与多发伤患者并发脓毒症有关。血浆氧化三甲胺的水平升高可能与肠道菌群的变化和多发伤患者并发多器官功能障碍综合征有关。

与肌少症发病相关的线粒体自噬靶点基因筛选及其在骨骼肌组织中表达观察

目的基于GEO数据库数据筛选与肌少症发病相关的线粒体自噬靶点基因,并观察其在肌少症患者骨骼肌组织中的表达变化。方法从GEO数据库检索肌少症的基因图谱数据,筛选肌少症发病的差异表达基因。从GeneCard数据库中检索并收集线粒体自噬相关基因。使用“VennDiagram”包将肌少症发病的差异表达基因与线粒体自噬相关基因取交集,得到与肌少症发病相关的线粒体自噬差异表达基因。运用基因本体论(GO)和京都基因与基因百科全书(KEGG)通路富集分析与肌少症发病相关的线粒体自噬差异表达基因的生物学功能,通过Cytoscape软件筛选与肌少症发病相关的线粒体自噬靶点基因,观察GSE136344基因表达图谱中肌少症、健康对照者骨骼肌与肌少症发病相关的线粒体自噬靶点基因表达情况。结果得到与肌少症发病相关的线粒体自噬差异表达基因99个。与肌少症发病相关的线粒体自噬差异表达基因主要涉及神经变性途径-多种疾病信号通路、帕金森疾病信号通路、朊毒体病信号通路等;主要调控能量代谢、细胞呼吸、氧化磷酸化调节等生物学过程,主要定位于线粒体内膜、线粒体内部的大分子蛋白质复合物等,参与调节跨膜转运活性等分子功能。与肌少症发病相关的线粒体自噬靶点基因有线粒体内膜蛋白基因(IMMT)、动态蛋白1样蛋白基因(DNM1L)及ATP合酶F1亚基α基因(ATP5A1)等;与正常骨骼肌组织相比,肌少症患者骨骼肌组织中IMMT、DNM1L表达低(P均<0.05)。结论与肌少症发病相关的线粒体自噬靶点基因为IMMT、DNM1L。与肌少症发病相关的线粒体自噬靶点基因可通过影响神经变性途径-多种疾病信号通路、帕金森疾病信号通路及朊毒体病信号通路等,参与调控能量代谢、细胞呼吸、氧化磷酸化调节等生物学过程,参与肌少症的发病。肌少症患者骨骼肌组织中IMMT、DNM1L低表达。

MOFs衍生的二氧化钛促进Ti-Fe_(2)O_(3)光阳极高效光电化学水氧化的多重效应

光电化学(PEC)分解水是一种清洁可持续的获取氢燃料的方法,其中产氧半反应(OER)是制约整个水分解过程效率的关键步骤.因此,光阳极的性能是决定太阳能到氢能转化效率的关键因素.在各种水氧化光阳极材料中,赤铁矿(α-Fe_(2)O_(3))因具有良好的化学稳定性、合适的带隙(~2.1 eV)、无毒、储量丰富等优点而成为最有前途的光阳极材料之一.然而,α-Fe_(2)O_(3)丰富的受体表面态和缓慢的水氧化动力学导致光生电荷复合严重,限制了其在光电化学中的实际应用.因此,有必要对α-Fe_(2)O_(3)进行表面工程设计以提高水氧化效率.本文提出了一种新方法,以金属有机框架(Ti-MOFs)为模板,在Ti-Fe_(2)O_(3)表面煅烧合成TiO_(2)层,然后将富活性位点的ZIF-67加载在TiO_(2)/Ti-Fe_(2)O_(3)上作为助催化剂,制备出具有较好光电化学性能的ZIF-67/TiO_(2)/Ti-Fe_(2)O_(3)复合光阳极.X射线衍射、高分辨透射电镜、X射线光电子能谱和拉曼光谱等表征结果证实成功合成了ZIF-67/TiO_(2)/Ti-Fe_(2)O_(3).同时,氮气等温吸附脱附曲线和表面接触角测试结果表明,MOFs衍生的TiO_(2)为介孔材料.采用表面光伏技术、光致发光光谱、飞秒-瞬态吸收光谱和电化学阻抗谱分析,研究了光生电荷的分离和复合行为.结果表明,MOFs衍生的TiO_(2)不仅可以作为钝化层有效抑制了表面复合,还作为Ti-Fe_(2)O_(3)的电子阻挡层,显著减少了电子向表面的流失,从而大大提高了Ti-Fe_(2)O_(3)表面和体相的电荷分离效率.进一步的累积电荷量测试、电化学阻抗谱和Bode图分析显示,负载MOFs衍生TiO_(2)后,可以明显促进光生空穴向电解质的注入,其多孔结构也可以增加反应接触面积,这有利于光生电荷在固液界面传输.此外,理论计算结果表明,Ti-Fe_(2)O_(3)水氧化速控步骤的能垒(ΔG=3.38 eV)明显高于TiO_(2)(ΔG=1.67 eV),说明OER更容易在TiO_(2)/Ti-Fe_(2)O_(3)表面发生,这与其光电流密度结果一致.为进一步提高反应活性和加快水氧化动力学,负载助催化剂ZIF-67后,ZIF-67/TiO_(2)/Ti-Fe_(2)O_(3)复合光阳极实现了较好的光电化学性能,其在1.23 V vs.RHE时光电流密度高达4.04 mA cm^(‒2),是Ti-Fe_(2)O_(3)的9.3倍,并且复合光阳极的入射光子电流转换效率和空穴注入效率分别达到93%(390 nm)和91%.综上所述,本研究通过MOFs衍生的TiO_(2)和ZIF-67助催化剂改性α-Fe_(2)O_(3)光阳极,显著提升了其光电化学水氧化性能.其中,MOFs衍生TiO_(2)不仅优化了电荷分离,还促进了光生空穴的注入,从而显著提高其光电化学水氧化性能.本研究为构筑高性能的有机-无机杂化光阳极提供了新思路.

多重雷击下线路避雷器氧化锌阀片的劣化特性试验

多重雷击会加速劣化氧化锌阀片,造成阀片的电、热性能急剧下降,不同多重雷击参数下氧化锌阀片的破坏具有显著差异性。为此,开展了不同多重雷击参数对氧化锌阀片劣化特性的研究:首先,搭建了多重雷击试验研究平台,对阀片进行了单重1.0倍额定电流、单重1.5倍额定电流、4重1.0倍额定电流、单重1.5倍额定电流和12重1.0倍额定电流的5种工况冲击试验,测试了阀片的直流参数和温升;其次,分析了多重雷击参数对试验结果的影响,最后对阀片的非线性系数、热应力和破坏形式进行了讨论。结果表明:不同工况下直流参考电压变化均呈“下降—平稳—下降”趋势,4重出现直流参考电压陡降现象,12重出现泄漏电流陡升现象;1.5倍额定电流工况下阀片泄漏电流在前期与标称电流工况的变化幅度相近,后期急剧劣化;非线性系数也存在“下降—平稳—下降”规律,增大冲击重数和幅值会使非线性系数下降趋势增大;冲击重数和幅值增大使阀片外圈处最大热应力增加,阀片外圈出现不同长度的缺块。

Temperature-sensing array using the metal-to-insulator transition of Nd_(x)Sm_(1-x)NiO_(3)

Rare-earth nickelates(RENiO_(3))show widely tunable metal-to-insulator transition(MIT)properties with ignorable variations in lattice constants and small latent heat across the critical temperature(TMIT).Particularly,it is worth noting that compared with the more commonly investigated vanadium oxides,the MIT of RENiO_(3)is less abrupt but usually across a wider range of temperatures.This sheds light on their alternative applications as negative temperature coefficient resistance(NTCR)thermistors with high sensitivity compared with the current NTCR thermistors,other than their expected use as critical temperature resistance thermistors.In this work,we demonstrate the NTCR thermistor functionality for using the adjustable MIT of Nd_(x)Sm_(1-x)NiO_(3)within 200–400 K,which displays larger magnitudes of NTCR(e.g.,more than 7%/K)that is unattainable in traditional NTCR thermistor materials.The temperature dependence of resistance(R–T)shows sharp variation during the MIT of Nd_(x)Sm_(1-x)NiO_(3)with no hysteresis via decreasing the Nd content(e.g.,x≤0.8),and such a R–T tendency can be linearized by introducing an optimum parallel resistor.The sensitive range of temperature can be further extended to 210–360 K by combining a series of Nd_(x)Sm_(1-x)NiO_(3)with eight rare-earth co-occupation ratios as an array,with a high magnitude of NTCR(e.g.,7%–14%/K)covering the entire range of temperatures.

Copper-Mediated Selective Multiple Inert Chemical Bonds Cleavage for Cyanation of Indoles via Tandem Carbon and Nitrogen Atom Transfer

Comprehensive Summary The activation of inert chemical bonds is an exciting area of research in chemistry because it enables the direct utilization of readily available starting materials and promotes atom-and step-economic synthesis.Undoubtedly,selectively activating and transforming multiple inert chemical bonds is an even more intriguing and demanding task in synthetic chemistry.However,due to its inherent complexity and extreme challenges,this endeavour is rarely accomplished.We report a copper-mediated complete cleavage and selective transformation of multiple inert chemical bonds of three easily available feedstocks,i.e.,a sp2C—H bond in indoles,three sp3C—H bonds and one C—N bond in a methyl carbon atom in TMEDA,and the C≡N triple bond in CH_(3)CN.This reaction proceeds via tandem carbon and nitrogen atom transfer,and allows for the direct and efficient cyanation of indoles,presenting a simple and direct alternative for synthesizing 3-cyanoindoles.

Vascular endothelium,a promising target for effectively treating fulminant diquat intoxication?

Following the withdrawal of paraquat,diquat(DQ)has emerged as the predominant herbicide.When people come into contact with or ingest DQ,may lead to poisoning and potentially fatal outcomes.Reports suggest that the mortality of DQ poisoning can be as high as 50%.DQ poisoning can be categorized as mild,moderate to severe or fulminant.In cases of fulminant poisoning,victims often succumb to multiple organ failure within 48 h.This presents a significant challenge in the clinical management.Scholars have discovered that oxidative stress,inflammatory injury,and cell apoptosis play crucial roles in the DQ poisoning.However,the underlying connection of the extensive organ damage remains unknown.The abnormal function and activity of endothelial cells(EC)should play a crucial role in tissue damage caused by DQ due to rich microcirculation and high sensitivity to perfusion in the vulnerable organs.However,reports on DQ-induced EC injury is rare.We made a preliminary discovery-the presence of severe vascular endothelial damage in the kidneys and lungs affected by DQ.Therefore,we hypothesize that DQ poisoning may be attributed to EC damage,ultimately resulting in multiple organ failure.

基于多重扫描速率法的α-Al_(2)O_(3)煅烧动力学研究

以氢氧化铝粉体为原料,探究氢氧化铝煅烧为α-Al_(2)O_(3)过程中的相转变与微观组织变化,利用多重扫描速率法对其煅烧过程进行动力学模拟计算。结果表明,氢氧化铝煅烧为α-Al_(2)O_(3)的优化条件为:煅烧温度1200℃、煅烧时间2 h、升温速率5℃/min。氢氧化铝煅烧过程出现3个吸热峰,对应3个失重阶段:第一阶段反应机理函数为G(α)=[(1-α)^(-1/3)-1]^2,反应平均活化能为91.16 kJ/mol,指前因子17.00×10^(9)~44.03×10^(9)min^(-1);第二阶段反应机理函数为G(α)=α~2,反应平均活化能为106.2 kJ/mol,指前因子7.70×10^(9)~18.60×10^(9)min^(-1);第三阶段反应机理函数为G(α)=α~(1/4),反应平均活化能为235.42 kJ/mol,指前因子39.94×10^(9)~50.79×10^(9)min^(-1)。

基于多模式的北京PM_(2.5)组分特征及氧化潜势分析

于2019年3、7月在中国气象科学研究院站进行PM_(2.5)样品采集与实验分析,并用正交矩阵因子分析法(PMF)模型进行来源解析,发现交通源(19.10%)、二次组分(19.17%)和扬尘源(18.02%)是采样期间PM_(2.5)污染主要来源.在此基础上以每立方米大气体积的抗坏血酸的消耗速率(OPv)表征PM_(2.5)的氧化潜势.3月北京的OPv值为(210.49±169.00)[pmol/(min·m^(3))],7月则为(313.34±131.84)[(pmol/(min·m^(3))).且OPv与Cu(r=0.801)、As(r=0.742)、SO_(4)^(2-)(r=0.701)等具有很强的相关性.将多元回归结果和WRF-Chem模型结合,构建了新的氧化潜势预测模型,发现OPv和PM_(2.5)浓度的空间特征存在差异,北京市OPv的浓度最大值出现在东南部.

含碳难处理金精矿生物预氧化-TCCA浸金实验研究

某含碳难处理金精矿中金含量15.9 g/t,铁、砷、硫和总碳的质量分数分别为23.17%、3.41%、24.7%和6.06%。金主要以次显微颗粒的形式被包裹于黄铁矿和砷黄铁矿中,同时碳引发“劫金”效应。本文针对该金精矿的特点开展了生物预氧化-TCCA(三氯异氰尿酸)浸金实验研究,建立多元线性回归模型分析浸金过程各因素对浸金效率的显著性影响。结果表明:经生物预氧化作用后,金精矿中硫和砷的分解效率分别可达63.59%和85.77%。拉曼光谱显示金精矿中碳质物缺陷减少,碳质物吸附能力下降。另外,多元线性回归模型分析显示,TCCA浓度、NaCl质量浓度和反应温度对浸金效率产生显著的影响,并呈正相关。TCCA浸金的最优化条件为:TCCA浓度0.22 mol/L,NaCl质量浓度30 g/L,反应温度45℃,矿浆中固体质量分数20%和反应时间3 h。在最优条件下,浸金效率可达87.49%,浸出液中金浓度为6.004 mg/L。