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Effects of high pressure roller grinding on size distribution of vanadium-titanium magnetite concentrate particles and improvement of green pellet strength

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Journal of Iron and Steel Research International 2017年第3期24卷 266-272页

作者： Feng Chen Yu-feng Guo Tao Jiang fu-qiang zheng Shuai Wang Ling-zhi Yang School of Minerals Processing and Bioengineering Central South University Changsha 410083 Hunan China

The vanadium-titanium magnetite concentrate from Panxi region of China was pretreated by high pressure roller grinding（ HPRG） and then used in pelletization. Size distribution change of the vanadiumtitanium magnetite concentrate after HPRG and the improvement of its green pellet strength were investigated. The results indicated that,besides the increase of fine particles,the vanadium-titanium magnetite concentrate after HPRG had a smaller size ratio of fine particle to coarse particle of 0. 126,meaning a lower porosity,compared with the size ratio of raw material of 0. 157. The concentrate particles were more closely packed when there was a smaller size ratio of fine particle to coarse particle. The particle packing in the green pellets was closer after HPRG,which strengthened the green pellets with an average drop number of 5. 1（ drop height of 0. 5 m） and average compressive strength of 13. 1 N per pellet of 11 mm in diameter.

关键词： High pressure roller grinding Particle packing Size distribution Size ratio Green pellet strength

Thermodynamics and phase transformations in the recovery of zinc from willemite

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1373-1379页

作者： Feng Chen Wei Chen Yu-feng Guo Shuai Wang fu-qiang zheng Tao Jiang Ze-qiang Xie Ling-zhi Yang School of Minerals Processing and Bioengineering Central South University

Willemite is a common component of zinc and lead metallurgical slags that, in the absence of effective utilization methods, cause serious environmental problems. To solve this problem and increase zinc recovery, we proposed a novel extraction method of zinc from willemite by calcified roasting followed by leaching in NH_4 Cl–NH_3·H_2 O solution. The thermodynamics and phase conversion of Zn_2 Si O_4 to zinc oxide(ZnO) during calcified roasting with CaO were investigated. The mechanism of mineralogical phase conversion and the effects of the CaO-to-Zn_2 Si O_4 mole ratio(n(Ca O)/n(Zn_2 Si O_4)), roasting temperature, and the roasting time on zinc-bearing phase conversion were experimentally investigated. The results show that Zn_2 Si O_4 was first converted to Ca_2 Zn Si_2 O_7 and then to ZnO. The critical step in extracting zinc from willemite is the conversion of Zn_2 Si O_4 to ZnO. The zinc percent leached in the ammonia leaching system rapidly increased because of the gradual complete phase conversion from willemite to ZnO via the calcified roasting process.

关键词： willemite zinc residues calcified-roasting thermodynamics mineralogical phase conversion

Gas-based reduction of vanadium titano-magnetite concentrate:behavior and mechanisms

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International Journal of Minerals,Metallurgy and Materials 2017年第1期24卷 10-17页

作者： Yu-lei Sui Yu-feng Guo Tao Jiang Xiao-lin Xie Shuai Wang fu-qiang zheng School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

The reduction of vanadium titano-magnetite pellets by H_2-CO at temperatures from 850 to 1050°C was investigated in this paper. The influences of pre-oxidation treatment, reduction temperature, and V_（H_2）/（V_（H_2）＋ VCO） on the metallization degree were studied. The results showed that pre-oxidation played a substantial role in the reduction of vanadium titano-magnetite pellets. During the reduction process, the metallization degree increased with increasing temperature and increasing V_（H_2） /（V_（H_2）＋ VCO）. The phase transformation of pre-oxidized vanadium titano-magnetite pellets during the reduction process under an H_2 atmosphere and a CO atmosphere was discussed, and the reduced samples were analyzed by scanning electron microscopy（SEM） in conjunction with back scatter electron（BSE） imaging. The results show that the difference in thermodynamic reducing ability between H_2 and CO is not the only factor that leads to differences in the reduction results obtained using different atmospheres. Some of Fe_（3-x）Ti_xO_4 cannot be reduced under a CO atmosphere because of the densification of particles＇ structure and because of the enrichment of Mg in unreacted cores. By contrast, a loose structure of particles was obtained when the pellets were reduced under an H_2 atmosphere and this structure decreased the resistance to gas diffusion. Moreover, the phenomenon of Mg enrichment in unreacted cores disappeared during H_2 reduction. Both the lower resistance to gas diffusion and the lack of Mg enrichment facilitated the reduction of vanadium titano-magnetite.

关键词： titano-magnetite ore reduction behavior mechanisms

Characteristics of the reduction behavior of zinc ferrite and ammonia leaching after roasting

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International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 26-36页

作者： Chao Wang Yu-feng Guo Shuai Wang Feng Chen Yu-jia Tan fu-qiang zheng Ling-zhi Yang School of Minerals Processing and Bioengineering Central South University

A novel method for recovering zinc from zinc ferrite by reduction roasting–ammonia leaching was studied in this paper. The reduction thermodynamic of zinc ferrite by CO was analyzed. The effects of roasting parameters on the phase transformation and conversion rate of zinc ferrite, and the leaching behavior of zinc from the reductive roasted samples by ammonia leaching, were experimentally investigated. The mineralogical phase compositions and chemical compositions of the samples were characterized by X-ray diffraction and chemical titration methods, respectively. The results showed that most of the zinc ferrite was transformed to zinc oxide and magnetite after weak reduction roasting. 86.43% of the zinc ferrite was transformed to zinc oxide under the optimum conditions: CO partial pressure of 25%, roasting temperature of 750°C, and roasting duration of 45 min. Finally, under the optimal leaching conditions, 78.12% of zinc was leached into the solution from the roasted zinc ferrite while all iron-bearing materials were kept in the leaching residue. The leaching conditions are listed as follows: leaching duration of 90 min,ammonia solution with 6 mol/L concentration, leaching temperature of 50°C, solid-to-liquid ratio of 40 g/L, and stirring speed of 200 r/min.

关键词： zinc ferrite reduction roasting ammonia leaching zinc extraction zinc-bearing waste

Transformation and separation of metallic iron in reduced ilmenite during corrosion process

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Journal of Iron and Steel Research International 2020年第12期27卷 1372-1381页

作者： fu-qiang zheng Xia Liu Yu-feng Guo Shuai Wang Feng Chen Ling-zhi Yang Tao Jiang Guan-zhou Qiu School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina Hunan Qingzhiyuan Environmental Protection Technology Co. Ltd.Changsha 410083HunanChina

The effects of corrosion temperature, oxygen flow rate and corrosion time on the transformation of metallic iron were systematically studied, and the effects of mineral phases of Fe-bearing products on Ti-Fe separation were investigated. The reaction mechanism of metallic iron in corrosion process was proposed. The results showed that corrosion temperature played a key role in determining the transformation of metallic iron in reduced ilmenite during corrosion process. Under suitable corrosion conditions, Fe-bearing mineral in reduced ilmenite could be converted to amorphous ferric hydroxide, lepidocrocite,hematite and magnetite, respectively, and lepidocrocite was the most easily separated Fe-bearing mineral from corrosion products owing to the significant density difference between lepidocrocite and Ti-rich materials. The Ti-rich material with 77.81 wt.% TiO2 and Fe-bearing product with 52.69 wt.% total Fe were obtained by gravity separation. The Ti recovery ratio and Fe recovery ratio were 91.16% and 86.27%, respectively.

关键词： Reduced ilmenite Corrosion Ti-rich material Fe-bearing mineral Lepidocrocite Metallic iron

The crosstalk between cellular survival pressures and N6-methyladenosine modification in hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2025年第1期24卷 67-75页

作者： Chu-Li fu zheng-Wei Zhao qiang-Nu Zhang Department of Hematology and Oncology Guangzhou Women and Children’s Medical CenterGuangzhou Medical UniversityGuangzhou 510623China Biomedicine Research Center Guangdong Provincial Key Laboratory of Major Obstetric DiseaseGuangdong Provincial Clinical Research Center for Obstetrics and Gynecologythe Third Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510150China

Background:Within the tumor microenvironment,survival pressures are prevalent with potent drivers of tumor progression,angiogenesis,and therapeutic resistance.N6-methyladenosine(m6 A)methylation has been recognized as a critical post-transcriptional mechanism regulating various aspects of mRNA *** the intricate interplay between survival pressures and m6 A modification pro-vides new insights into the molecular mechanisms underlying hepatocellular carcinoma(HCC)progres-sion and highlights the potential for targeting the survival pressures-m6 A axis in HCC diagnosis and *** sources:A literature search was conducted in PubMed,MEDLINE,and Web of Science for relevant articles published up to April *** keywords used for the search included hepatocellular carcinoma,cellular survival,survival pressure,N6-methyladenosine,tumor microenvironment,stress response,and ***:This review delves into the multifaceted roles of survival pressures and m6 A RNA methylation in HCC,highlighting how survival pressures modulate the m6 A landscape,the impact of m6 A modifica-tion on survival pressure-responsive gene expression,and the consequent effects on HCC cell survival,proliferation,metastasis,and resistance to ***,we explored the therapeutic potential of targeting this crosstalk,proposing strategies that leverage the understanding of survival pressures and m6 A RNA methylation mechanisms to develop novel,and more effective treatments for ***:The interplay between survival pressures and m6 A RNA methylation emerges as a complex regulatory network that influences HCC pathogenesis and progression.

关键词： Hepatocellular carcinoma N6-methyladenosine methylation Hypoxia Target therapy Survival pressure

Early and long-term results of combined cardiac surgery and neoplastic resection in patients with concomitant severe heart disease and neoplasms

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Chinese Medical Journal 2011年第13期124卷 1939-1942页

作者： fu qiang LI Quan-zheng LIANG De-gang RUAN Xin-hua WANG Zan-xin WEI Min-xin Department of Cardiovascular Surgery Tianjin Medical UniversityGeneral Hospital Tianjin 300052 China

Background It is a surgical dilemma when patients present with both severe heart disease and neoplasms. The best surgical treatment remains controversial. This study aimed to analyze the early and long-term results of simultaneous surgical treatment of severe heart disease and neoplasms. Methods We reviewed the clinical records of 15 patients who underwent simultaneous neoplastic resection and cardiac surgery between September 2006 and January 2011. There were 5 male and 10 female patients. The mean age was （59.2±12.5） years and the mean left ventricular ejection fraction was （57.4±11.0）%. All patients were followed up completely for a period of 12 to 51 months （mean, （33.1±11.2） months）. Results Fifteen patients underwent simultaneous cardiac surgery and neoplastic resection. Cardiac procedures consisted of off pump coronary artery bypass grafting （n=7）, aortic valve replacement （n=3）, mitral valve replacement （n=3）, mitral valve replacement with coronary artery bypass grafting （n=1） and left atrial myxoma resection （n=1）. Neoplastic resection consisted of lung cancer resection （n=5）, colonic cancer resection （n=3）, gallbladder resection （n=1）, colonic cancer resection with gallbladder resection （n=1）, hysterectomy （n=2）, hysterectomy with bilateral salpingo-oophorectomy （n=2） and left ovariectomy （n=1）. Pathological examination confirmed malignant disease in 10 patients and benign disease in 5 patients. There were no perioperative myocardial infarctions, stroke, pericardial tamponade, renal failure or hospital deaths. The most frequent complications were atrial fibrillation （33.3%）, pneumonia （26.7%）, low cardiac output syndrome （6.7%） and delayed healing of surgical wounds （6.7%）. There was 1 late death 42 months after surgery for recurrent malignant disease. At 1 and 3 years, survival rates were 100% （Kaplan-Meier method）. Conclusions Simultaneous cardiac surgery and neoplastic resection was not associated with increased early or late morbidity or mortality. Car

关键词： combined operation cardiac surgery, neoplastic resection

Behavior of vanadium during reduction and smelting of vanadium titanomagnetite metallized pellets

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Transactions of Nonferrous Metals Society of China 2020年第6期30卷 1687-1696页

作者： Shuai WANG Yu-feng GUO fu-qiang zheng Feng CHEN Ling-zhi YANG Tao JIANG Guan-zhou QIU School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

The effects of CaO content,MgO content and smelting temperature on the vanadium behavior during the smelting of vanadium titanomagnetite metallized pellets were *** thermodynamics of reduction and distribution of vanadium was analyzed and the high-temperature smelting experiments were carried *** thermodynamic calculations show that the distribution ratio of vanadium between the slag and the hot metal decreases with the increments of CaO and MgO content in the slag as well as the increase of the smelting *** smelting experiments demonstrate that the vanadium content in iron and the recovery rate of vanadium in pig iron increase as the CaO content,MgO content and smelting temperature increase,whereas the vanadium distribution ratio between the slag and iron tends to ***,the recovery rate of vanadium in pig iron has a rising trend with increasing the optical basicity of the *** addition of MgO in the slag to increase the slag optical basicity can not only improve the vanadium reduction but also promote the formation of magnesium-containing anosovite,which is beneficial to following titanium extraction.

关键词： vanadium vanadium titanomagnetite vanadium distribution ratio electric-furnace titanium slag MgO

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云南边境缅籍务工人员管理问题研究

云南民族大学学报（哲学社会科学版） 2015年第5期32卷 21-27页

作者：付正强黎尔平昆明理工大学管理与经济学院云南昆明650093

目前,中国境内的"三非"务工人员的最大的问题是境外务工人员管理规定已经不适应现实的要求。对它的解决,是正视全球化背景下,必然带来的劳动力流动和劳动力资源再配置,这是不可回避的事实。在云南中缅边境地区,资本的逐利性同样使得缅... 详细信息

目前,中国境内的"三非"务工人员的最大的问题是境外务工人员管理规定已经不适应现实的要求。对它的解决,是正视全球化背景下,必然带来的劳动力流动和劳动力资源再配置,这是不可回避的事实。在云南中缅边境地区,资本的逐利性同样使得缅籍务工人员成为了中国乃至全球劳动力市场分工的一部分。作为云南边境外籍劳工的最大集中地——德宏州政府于2014年初实施的《德宏州境外边民入境务工管理暂行办法》,手续简洁,并与一定的社会保障相联系,推动了更多的缅籍务工者愿意配合地方管理部门获取合法身份。德宏州为境外边民务工人员提供的基本社会保障,既体现人道主义精神,规范了劳动力市场,避免企业雇佣境外廉价务工人员而排挤国内工人,同时也表明中国与周边国家共同富裕的愿望和责任。

关键词：缅籍务工人员社会管理社会保障公共服务