检索结果-南通市图书馆

Advances in Chemical Engineer.ng and Science 2013年第3期3卷 171-177页

作者： Alejandr. Valenzuela Jesús L. Valenzuela josé r. parga Depar.ment of Chemical Engineer.ng and Metallur.y University of Sonora Hermosillo México

The major.ty of the r.fr.ctor. gold and silver.occur. in occlusion in sulphides, then pr.cious metal dissolution is possible by fir.t oxidizing aur.fer.us sulfide concentr.te using sodium hypochlor.te-sodium-hydr.xide solution followed of pr.ssur. cyanidation of the oxidized concentr.te, for.the extr.ction of pr.cious metals. This pr.cess was conducted and evaluated under.cyanide and oxygen pr.ssur.. This ver.atile appr.ach offer. many advantages, including low temper.tur.s, low pr.ssur. and less costly mater.als of constr.ction than conventional pr.ssur. oxidation. In this study, the effect of oxygen pr.ssur., concentr.tion of sodium hypochlor.te, temper.tur., and initial pH, in pr.cious metals r.cover. and As r.moval wer. evaluated using a 24 factor.al design. Char.cter.zation of the or.s showed that pyr.te and ar.enopyr.te wer. the main miner.ls pr.sent on the concentr.te. The best r.sults for.gold extr.ction wer. obtained with oxygen pr.ssur. of 80 psi, 10% (w/w) sodium hypochlor.te, temper.tur. of 80℃, at pH = 13, and a constant stir.ing speed of 600 r.m. These conditions allowed an appr.ximated 60% of gold and 90% of silver.extr.ctions in 1 hr.

关键词： r.fr.ctor. Gold Concentr.te Hypochlor.te Oxidation Pr.tr.atment Pr.ssur. Cyanidation

Copper.and Cyanide r.cover. in Cyanidation Effluents

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineer.ng and Science 2011年第4期1卷 191-197页

作者： josé r. parga Jesús L. Valenzuela Héctor.Mor.no Jaime E. Pér.z 不详

Cyanidation is the main pr.cess for.gold and silver.r.cover. fr.m its or.s. In this study, a pr.cess is pr.posed to r.cover.copper.and cyanide fr.m bar.en solutions fr.m the Mer.ill-Cr.we cementation pr.cess with zinc dust. This technology is based on inducing nucleated pr.cipitation of copper.and silver.in a ser.entine r.actor. using sodium sulfide as the pr.cipitator. and sulfur.c acid for.pH contr.l. r.sults show that pH value has a significant effect on copper.cyanide r.moval efficiency, and it was deter.ined the optimal pH r.nge to be 2.5 - 3. At this pH value, the copper.cyanide r.moval efficiency achieved was up to 97 and 99%, when copper.concentr.tion in the influent was 636 and 900 ppm. r.spectively. In this pr.cess (sulphidization-acidification-thickening-HCN r.cycling), the cyanide associated with copper.cyanide complexes, is r.leased as HCN gas under.weakly acidic conditions, allowing it to be r.cycled back to the cyanidation pr.cess as fr.e cyanide. Cyanide r.cover. was 90%. Finally, this pr.cedur. was successfully r.n at Miner. William in México.

关键词： Pr.cipitation Cyanide r.moval Copper r.cover. Cyanidation

Copper.r.cover. fr.m Bar.en Cyanide Solution by Using Electr.coagulation Ir.n Pr.cess

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineer.ng and Science 2013年第2期3卷 150-156页

作者： josé r. parga Guiller.o Tibur.io Munive Jesús L. Valenzuela Víctor.V. Vazquez Gr.gor.o González Zamar.ipa Institute Technology of Saltillo Saltillo Mexico

This paper.is a br.ef over.iew of the r.le of inducing the nucleated electr. winning of copper.by using ir.n electr.des in electr.coagulation (EC) pr.cess. Cyanide compounds ar. widely used in gold or. pr.cessing plants in or.er.to facilitate the extr.ction and subsequent concentr.tion of the pr.cious metal. Owing to cyanide solution employed in gold pr.cessing, effluents gener.ted have high contents of fr.e cyanide as well as copper.cyanide complexes, which lend them a high degr.e of toxicity. In this r.gar., two options for.the tr.atment of cyanide bar.en solutions has been used;in two ways;fir.t for.cyanide destr.ction by oxidation with the use of the EC pr.cess, in theor., has the advantage of decomposing cyanide at the anode and collecting copper.simultaneously by a sludge of copper.magnetic ir.n. In both cases excellent per.or.ance can be achieved using the high capacity of the bipolar.ir.n EC technology. We found that it is possible to r.duce the copper.cyanide complex fr.m 720 mg·l-1 to below 10 mg·l-1 within 20 minutes.

关键词： Copper r.cover. Electr.coagulation Pr.cess Bipolar Ir.n Electr.des Cyanide

Kinetic Aspects of Gold and Silver.r.cover. in Cementation with Zinc Power.and Electr.coagulation Ir.n Pr.cess

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineer.ng and Science 2012年第3期2卷 342-349页

作者： Gabr.ela V. Figuer.a Mar.inez josé r. parga Tor.es Jesús L. Valenzuela Gar.ía Guiller.o C. Tibur.io Munive Gr.gor.o González Zamar.ipa Depar.ment of Chemical Engineer.ng and Metallur.y University of Sonora Hermosillo México Depar.ment of Metallur.y and Mater.als Science Institute of Technology of Saltillo Saltillo México

The Mer.ill-Cr.we or.Cementation pr.cess is used for.concentr.tion and pur.fication of gold and silver.fr.m cyanide solutions. Among other.available options for.r.cover. of pr.cious metals fr.m cyanide solutions, Electr.coagulation (EC) is a ver. pr.mising electr.chemical technique for.the r.cover. of this pr.cious metals. In this wor. fir.t, an intr.duction to the fundamentals of the Mer.ill Cr.we and EC pr.cess ar. given, then Kinetic aspects conditions and r.sults of the both pr.cess, for.the r.moval of gold and silver.fr.m cyanide solutions ar. pr.sented, and finally the char.cter.zation of the solid pr.ducts for.ed dur.ng the EC pr.cess with X-r.y Diffr.ction and SEM ar. shown. r.sults suggests that The cementation of both gold and silver.by suspended zinc par.icles confor.s to well-behaved fist or.er.kinetics and for.the EC pr.cess the r.sults show that is an excellent option to r.move Au and Ag fr.m cyanide solution by using ir.n electr.des. Finally, 99.5% of gold and silver.wer. r.moved in the exper.mental EC r.actor. and it was achieved in 5 minutes or.less.

关键词： Cyanidation Mer.ill Cr.we Electr.coagulation Kinetics

New Appr.ach for.Lead, Zinc and Copper.Ions Elimination in Cyanidation Pr.cess to Impr.ve the Quality of the Pr.cipitate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mater.als Sciences and Applications 2015年第2期6卷 117-129页

作者： josé r. parga Jesús V. Valdés Jesús L. Valenzuela Gr.gor.o Gonzalez L. Mar.a de J. Pér.z T. Fr.ncisco Cepeda Depar.ment of Mater.als Science and Metallur.y Technological Institute of Saltillo Saltillo M&eacute xico Depar.ament of Chemical Engineer.ng and Metallur.y University of Sonora Hermosillo M&eacute xico Faculty of Metallur.y University of Coahuila Monclova M&eacute xico

The Mer.ill-Cr.we zinc-pr.cipitation pr.cess has been applied wor.dwide on a lar.e number.of oper.tions for.r.cover.ng gold and silver.fr.m cyanide solutions. However. in some of the lar.e plants this pr.cipitate is of low quality, because copper.and especially lead ar. pr.cipitated along with gold and silver.r.sulting in a higher.consumption of zinc powder. fluxes in the smelting of the pr.cipitate, for.ation of mate and shor. life for.cr.cibles. In this r.sear.h, a method is pr.posed to r.cover.lead, zinc and copper.cyanide ions fr.m bar.en solutions, fr.m the Mer.ill-Cr.we pr.cess with hydr.xyapatite befor. the filter.pr.ss. This technology is based on inducing nucleated pr.cipitation of zinc, copper.and silver.ions in a ser.entine r.actor. using sodium sulfide as the pr.cipitator.and sulfur.c acid for.pH contr.l. This pr.cedur. was successfully applied at WILLIAM Mining and BACIS Mining Gr.up in México.

关键词： Gold-Silver r.cover. Hydr.xyapatite Mer.ill-Cr.we Sulphide Pr.cipitation

Combined cell-based ther.py str.tegies for.the tr.atment of Par.inson's disease:focus on mesenchymal str.mal cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neur.l r.gener.tion r.sear.h 2023年第3期18卷 478-484页

作者： Jannette r.dr.guez-Pallar.s Mar.a Gar.ía-Gar.ote Juan A.parga joséLuis Labandeir.-Gar.ía Labor.tor. of Cellular.and Molecular.Neur.biology of Par.inson´s Disease Research Center for Molecular Medicine and Chronic Diseases(CiMUS)IDISDepartment of Morphological SciencesUniversity of Santiago de CompostelaSantiago de CompostelaSpain Networ.ing r.sear.h Center.on Neur.degener.tive Diseases(CIBEr.ED) MadridSpain

Par.inson’s disease is a neur.degener.tive condition char.cter.zed by motor.impair.ents caused by the selective loss of dopaminer.ic neur.ns in the substantia *** is an effective and well-toler.ted dopamine r.placement ***,levodopa pr.vides only symptomatic impr.vements,without affecting the under.ying pathology,and is associated with side effects after.long-ter. ***-based r.placement is a pr.mising str.tegy that offer. the possibility to r.place lost neur.ns in Par.inson’s disease *** studies of tr.nsplantation of human fetal ventr.l mesencephalic tissue have pr.vided evidence that the gr.fted dopaminer.ic neur.ns can r.inner.ate the str.atum,r.lease dopamine,integr.te into the host neur.l cir.uits,and impr.ve motor.*** of the limiting factor. for.cell ther.py in Par.inson’s disease is the low sur.ival r.te of gr.fted dopaminer.ic *** factor. could cause cell death of dopaminer.ic neur.ns after.gr.fting such as mechanical tr.uma,gr.wth factor.depr.vation,hypoxia,and *** factor. play an essential r.le in the sur.ival of gr.fted ***,dir.ct,timely,and contr.llable deliver. of neur.tr.phic factor. into the br.in faces impor.ant *** types of cells secr.te neur.tr.phic factor. constitutively and co-tr.nsplantation of these cells with dopaminer.ic neur.ns r.pr.sents a feasible str.tegy to incr.ase neur.nal *** this r.view,we pr.vide a gener.l over.iew of the pioneer.ng studies on cell tr.nsplantation developed in patients and animal models of Par.inson’s disease,with a focus on neur.tr.phic factor.secr.ting cells,with a par.icular.inter.st in mesenchymal str.mal cells;that co-implanted with dopaminer.ic neur.ns would ser.e as a str.tegy to incr.ase cell sur.ival and impr.ve gr.ft outcomes.

关键词： br.in r.pair cell r.placement co-gr.fts dopaminer.ic neur.ns fetal ventr.l mesencephalic tissue mesenchymal stem cells neur.l gr.fting neur.l tr.nsplantation neur.blasts neur.tr.phic factor.

r.moval of Aqueous Lead and Copper.Ions by Using Natur.l Hydr.xyapatite Powder.and Sulphide Pr.cipitation in Cyanidation Pr.cess

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mater.als Sciences and Applications 2013年第4期4卷 231-237页

作者： josé r.fugio parga Jesús Leobar.o Valenzuela Víctor.Vazquez Mar.o r.dr.guez Héctor.Mor.no Depar.ament of Chemical Engineer.ng and Metallur.y University of Sonora Hermosillo Mexico Depar.ment of Chemistr. Institute Technology of Laguna Torreon Mexico Depar.ment of Metallur.y and Mater.als Science Institute Technology of Saltillo Saltillo Mexico

Mining, or. pr.cessing, and smelting activities have contaminated soil and water.r.sour.es with cyanide and heavy metals thr.ughout the wor.d. In-situ chemical immobilization is a r.mediation technology that decr.ases the concentr.tions of dissolved ions of copper.cyanide and lead hydr.xides by adsor.tion or.pr.cipitation. This study deals, with a pr.cess to r.cover.lead hydr.xides with natur.l hydr.xyapatite powder.and copper.cyanide ions with sulphide pr.cipitation fr.m solutions of the cyanidation pr.cess. This technology is based on inducing nucleated pr.cipitation of copper.and silver.in a ser.entine r.actor. using sodium sulfide as the pr.cipitator. and sulfur.c acid for.pH contr.l. r.sults show that pH value has a significant effect on copper.cyanide r.moval efficiency, and it was deter.ined the optimal pH r.nge to be 2.5 - 3. At this pH value, the copper.cyanide r.moval efficiency achieved was up to 99% with 60 per.ent of copper.pur.ty and the cyanide ions associated with this complex the r.cover. was 90%. For.the elimination of lead hydr.xides ions fr.m the aqueous cyanidation pr.cess with natur.l hydr.xiapatite powder.the r.cover. was 99%. The abundance of cow bones, its low pr.ce and non-aggr.ssive natur. towar.s the envir.nment ar. advantages for.its utilization in point of view of wastewater.cleanup and Dor. with higher.quality.

关键词： Natur.l Hydr.xyapatite Sulphide Pr.cipitation Zinc Cementation

r.cover. of Silver.fr.m Cyanide Solutions Using Electr.chemical Pr.cess Like Alter.ative for.Mer.ill-Cr.we Pr.cess

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mater.als Sciences and Applications 2014年第12期5卷 863-870页

作者： Víctor.Vázquez josé parga Jesús L. Valenzuela Gabr.ela Figuer.a Alejandr. Valenzuela Guiller.o Munive Depar.ment of Chemical Engineer.ng and Metallur.y University of Sonora Hermosillo Mexico Depar.ment of Mater.als Science and Metallur.y Technological Institute of Saltillo Saltillo Mexico

The conventional pr.cesses for.r.cover. of silver.fr.m cyanide leach solutions ar. the car.on adsor.tion, the Mer.ill-Cr.we zinc dust cementation, the Ion Exchange, and Solvent Extr.ction pr.cesses;among other.available options for.r.cover. of pr.cious metals fr.m cyanide solutions, Electr.coagulation (EC) is a ver. pr.mising electr.chemical pr.cess that does not r.quir. high concentr.tions of silver.in cyanide solutions to yield excellent r.sults and neither.pr.tr.atment of cyanide solutions like Mer.ill-Cr.we pr.cess (deoxygenating and clar.fication). The pr.sent study has been done for.the r.cover. of silver.contained in pr.gnant solution fr.m the cyanidation pr.cess using the electr.coagulation technology with ir.n electr.des, and ther.for. develops an alter.ative technology for.Mer.il-Cr.we pr.cess. The aver.ge silver.content in pr.gnant solution was of 52 ppm, r.cover. was obtained of 99% of silver. with this optimum oper.ting par.meter., pH = 8, r.sidence time = 20 minutes and conductivity by addition of sodium chlor.de = 4 gr./L. Finally the char.cter.zation of the solid pr.ducts for.ed dur.ng the EC pr.cess with X-r.y Diffr.ction and Scanning Electr.nic Micr.scope was per.or.ed, r.sults suggest that magnetite par.icles and amor.hous ir.n oxyhydr.xides ar. pr.sent (Lepidocr.cite).

关键词： Electr.chemical Pr.cess Silver Cyanides Magnetic Fields Mer.ill-Cr.we

Copper.and Cyanide r.cover. in Cyanidation Effluents

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论