Mechanisms of flotation separation of diaspore and kaolinite by quaternary ammonium salt DTAL

The FTIR spectroscopy indicates that the adsorption of quaternary ammonium salt DTAL on the dia-spore and kaolinite is physical adsorption. The adsorption of cationic surfactants measured by two-phase titration shows that the adsorption on the kaolinite is notably more than that on diaspore. The adsorption isotherm on ka-olinte is linear while that of DTAL on diaspore is two-step flat form. The analysis on the cationic ions of kaolinite supernatants shows that kaolinite releases plenty of crystalloid structure ions which countervail the crystalloid charge because of the adsorption of the cationic surfactant. The mechanisms of the quaternary ammonium salt DTAL on flotation separation of diaspore and kaolinite include ion exchange interaction as well as electrostatic force.     

Reverse flotation separation on diaspore and kaolinite in the presence of cationic polyacrylamide polymers

1　INTRODUCTIONChinaisrichindiasporebauxiteresources[1,2 ]whichpossessspecialpropertiessuchashighgradeofbothAl2 O3andSiO2 andlowFecontent,buttheAl/Si(massratioofAl2 O3toSiO2 )valueislow .Inordertotreatthediasporebauxite ,unitedmethodsandsin teringmethods[3] arestillappliedalthoughsufferingfromdisadvantagesincludingcomplextechnologyflowchart,highenergyconsumption ,highproduc tioncost ,andrestrainingfurtherdevelopmentofalu minaindustry .However ,byimprovingbauxiteAl/Si>10 ,wecanchoosem…     

Flotation of kaolinite and its interaction with hexadecylammonium bromide

1　INTRODUCTIONAshasbeenextensivelydiscussedinRef .[1],theselectiveseparationofbauxiteisextremelycom plexinseveralcases ,theproblemsinvolvedarenotyetfullyresolved .Thetechnologicalschemesofposi tive flotationorreverse flotationseparationofalu minum silicatemineralsfromdiasporicbauxiteweresuggested[2 ,3] .The positive flotationseparationofbauxiteisfinishedbydepressingaluminumsilicateganguemineralssuchasillite ,kaoliniteandpy rophillite,andusesanioniccollectorstofloatdias pore .Phosphate ,s…     

Cleavage nature,electrokinetics,aggregation and dispersion of kaolinite

1　INTRODUCTIONKaoliniteiscurrentlyusedinceramics ,papermanufacturing ,medicalapplications ,agriculturalchemicals ,chemicalengineering ,refractorymaterialanddefenseindustrybecausekaolinitehasmanyhighprocessingpropertiesasanindustrialmineralduetoitssurfaceproperties[1,2 ] .Inreverseflotationofdi asporicbauxite ,whichisveryimportantforthein dustryofaluminumoxideproduction ,kaoliniteisneededtoberemoved .Therefore ,Itisusefultoun derstandthecrystalstructure ,cleavagenature ,sur faceelectrokin…     

Effect and mechanism of diphosphonic acid on flotation characteristic of fersmite and intergrowth gangue

1　INTRODUCTIONThereservesofniobium containingmineralsinChinatakethesecondplaceintheworld ,anddis tributemainlyinBaiyuneboofInnerMongolia ,TaimeiofGuangdongProvinceandYichunofJiangxiProvince ,etc .Niobium containingmineralsweredis coveredover 130kinds ,butonlyafewofthemhadindustrialvalue .Fersmiteisoneoftheseveralvaluedindustrialniobium containingminerals[1,2 ] .Theprocessingofniobium containingmineralsistoodifficultduetotheirfinesizeandnumerousspeciesandcomplexcomposing .Inmiddleperi…     

Effects of impeller speed and aeration rate on flotation performance of sulphide ore

1 Introduction Aeration rate and impeller speed are important operational variables in flotation and controlling of them is significant for improving the flotation performance. LAPLANTE et al[1, 2] studied the effect of aeration rate on the flotation rate…     

Sulphidization flotation for recovery of lead and zinc from oxide-sulfide ores

A new flowsheet was developed to recover the valuable minerals from oxide or oxide-sulfide ores of lead and zinc. The flowsheet consisted of flotation of sulfide minerals, desliming and sulphidization-flotation of oxide minerals. The corresponding reagent system and techniques to the flowsheet were investigated. Batch and continuous tests show that the dosage of sodium sulfide, temperature, and collector type are main affecting factors on the recovery of smithsonite and cerussite. For the flotation of cerussite, there is an appropriate dosage of sodium sulfide at which the recovery reaches its maximum value. The required sodium sulfide for smithsonite flotation is higher than that for cerussite and the recovery of smithsonite flotation increases with the dosage of sodium sulfide at low level and becomes insensitive at high dosage. The appropriate temperature for smithsonite and cerussite flotation is found to be 25 ～ 40℃. Amines are found to be the effective collectors for the flotation of smithsonite after sulphidization. Investigation also shows that desliming prior to sulphidization-flotation is essential to the effective recovery of smithsonite and cerussite, and the desliming process of two-stage hydrocyclon is well feasible and effective for the treatment of lead-zinc oxide ores. A further treatment on the cerussite flotation concentrate by shaking table is proposed to obtain higher lead grade.     

Flow of gas-liquid-solid system and its application in packed flotation column

A packed flotation column, which is packed with multiple board ripple packings, was described. Based on comprehensive steady state models, chemical reactor developed previously in chemical engineering subjects, have been extended to packed flotation column for mineral separation. The experimental results verify that tarts in series model is better than axially-dispersed plug flow model to describe flow pattern in the collection zone of column by RTD (residence time distribution), and the error of experimental data and calculated data of both models are 0. 07 % - 0. 1% and 0. 18 % - 0.45 % respectively. And, RTD of gas phase was also considered, results also show that gas in the whole column appears plug flow. The cleaning process through adding wash water in froth zone of column was described, and the effect of superficial air vdodty and superficial wash water vdocity on the cleaning action of froth zone were discussed. Flotation experiment for single column was conducted for phosphate ores. The recovery for P2Os was 85.8%, and the grade was 26.8%.     

Synthesis of N-decyl-1,3-diaminopropanes and its flotation propertieson aluminium silicate minerals

1　INTRODUCTIONBauxiteisamajorsourceforaluminaproduction .Bayerprocessfeaturesshortresidencetime ,lowener gyconsumptionandhigh qualityproduct .Asare sult ,itiswidelyusedtotreatthebauxiteofalu minum/silicateratio (A/S)morethan 8.AlthoughthereareabundantaluminiumoxidemineralresourcesinChina ,mostofthemarediasporicbauxitewithhighaluminumcontent ,butlowA/Sratio .Among4 0bauxitediggings ,theaverageAl2 O3andSiO2 con tentsare 6 3.4 1%and 11.5 9% ,respectively ,whiletheaverageA/Sratiois4 6 […     

Structure–activity relationship and mechanisms of reagents used in scheelite flotation

Effects of carboxylic acid collector,benzohydroxamic acid(BHA),sodium hexametaphosphate(SHAP),sodium silicate,and oxalic acid on scheelite flotation were studied through flotation tests,quantum chemical calculation,and flotation solution computational chemistry.In terms of the calculation results,the relationship between chemical reactions occurring on the scheelite surface and molecular structures of the reagents were analyzed.The results show that BHA and carboxylic acid collectors interact with scheelite in different forms and the recovery of scheelite using sodium oleate as collector declines successively from SHAP,sodium silicate,to oxalic acid.Moreover,it is found that the performance of depressant in scheelite flotation is directly related to the group electronegativity,indicating that the latter is a dominant factor that determines the former.These findings will be helpful to the academic research communities of scheelite flotation.     

Bioleaching of marmatite flotation concentrate by Acidithiobacillus ferrooxidans and Leptospirillum f errooxidans

Bioleaching of marmatite flotation concentrate by Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans was investigated at 35℃, the initial pH value of 2.0 on an orbital shaker with 160 min^-1 over a period of 10 days. Experimental results indicate that the adapted strains increase markedly the dissolution rate and the leac-hing ratio of marmatite. Pulp density also affects the bioleaching of marmatite. Massive elemental sulfur and jarosite form during the leaching process in the systems inoculating the adapted strains in pure and mixed cultures;and acid product is enhanced, which decreases the pH below to 2.0 in latter leaching period. Marmatite preferentially dis-solves during the bacterial leaching of complex sulfides. Compared with the pure cultures of original and adapted strains, the adapted strains of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans in mixed cultures are more efficient in the oxidation of marmatite.     

Preliminary examination of electrochemical and spectroscopic features of trithiocarbonate collectors for sulfide mineral flotation

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅｔｈｅ 192 0’ｓ ,ｔｈｅｄｉｔｈｉｏｃａｒｂｏｎａｔｅｓ (ｘａｎ ｔｈａｔｅｓｏｒＤＴＣ)ｈａｖｅｂｅｅｎｔｈｅｐｏｐｕｌａｒｃｏｌｌｅｃｔｏｒｓｏｆｃｈｏｉｃｅｆｏｒｓｕｌｆｉｄｅｍｉｎｅｒａｌｆｌｏｔａｔｉｏｎ .Ｔｈｅｙｈａｖｅｓｅｖｅｒａｌａｄｖａｎｔａｇｅｓｏｖｅｒｏｔｈｅｒｃｏｌｌｅｃｔｏｒｓｉｅｔｈｅｙａｒｅｉｎｅｘｐｅｎ ｓｉｖｅ ,ｅａｓｙｔｏｐｒｏｄｕｃｅ ,ａｖａｉｌａｂｌｅｉｎｓｏｌｉｄｆｏｒｍ ,ｔｏｔａｌｌｙｗａｔｅｒ ｓｏｌｕｂｌｅａｎｄｖ…     

Relationship between solids flux and froth features in batch flotation of sulphide ore

The froth features in the batch flotation of a sulphide ore were investigated by using the digital image parameters of the froth, the small number emphasis（Nsne）, the average grey level（Dagl） and the instability number （Nins）, under different conditions of impeller speeds and aeration rates. It is found that the value of Nsne is strongly dependent on the average bubble size of the froth and Dagl on the volume fraction of solid in the froth, and the froth features during the batch flotation are influenced by impeller speed and aeration rate. A kinetic model of the concen- trate solid flux was developed which relates the flotation process to the image parameters, Nsne and Dagl of the froth and predictions are well consistent with the experimental data.     

The Property of Alkylthiophosphoric Cobalt and Separation of Co(Ⅱ) and Ni(Ⅱ)

ＴｈｅＰｒｏｐｅｒｔｙｏｆＡｌｋｙｌｔｈｉｏｐｈｏｓｐｈｏｒｉｃＣｏｂａｌｔａｎｄＳｅｐａｒａｔｉｏｎｏｆＣｏ（Ⅱ）ａｎｄＮｉ（Ⅱ）ＬｉｕＸｉｎｇｚｈｉａｎｄＸｕｅＨｏｎｇ（刘兴芝）（薛红）ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｌｉａｏｎｉｎｇ...     

Ni(001)/Ni_3Nb(001)面界面性质的第一性原理研究(英文)

采用第一性原理赝势平面波的方法研究Ni(001)、Ni3Nb(001)表面和Ni/Ni3Nb(001)界面。计算界面终端为Ni或Ni+Nb,堆积方式为顶部位置或空心位置这4种界面模型的粘附功、稳定性及电子结构。结果表明:Ni(001)和Ni3Nb(001)表面具有8个原子层时展现出较好的体相似性;以Ni+Nb为界面终端,堆积方式为空心位置的界面模型具有最大的结合强度和临界裂纹扩展应力,且具有最好的热稳定性。该模型界面处的Ni原子和Nb原子之间是共价键,这主要是由Nb 4d和Ni 3d轨道的电子贡献的。比较Ni/Ni3Nb(001)界面和Ni/Ni3Al(001)界面的性质可知,前者的热稳定性比后者的差,且更难形成界面,但是Ni/Ni3Nb(001)界面的形成能改善镍基合金的力学性能。     

Nature of magnetic and electronic structure of double perovskite A2FeMoO6

The nature of magnetic and electronic structure in double perovskite structure A2FeMoO6 （A= Sr, a, Ca） was calculated using the local spin density approximation （LSDA） and the LSDA＋U Coulomb interaction method of density functional theory. The result shows that Sr2FeMoO6 is magnetic metallic material, whereas Ba2FeMoO6 and Ca2FeMoO6 are half-metallic materials. Fe has great effect on the magnetic property of double perovskite structure A2FeMoO6 materials. Because of the orbit hybridization and polarization between the metal element and O element, the Mo element has magnetic properties. The static magnetic moment of double perovskite structure A2FeMoO6 materials, the value of the magnetic moment of these A2FeMoO6 for （A=Ca, Sr, Ba） are 3.626 43μB, 2.678 64μB, 3.706 17μB, respectively. The magnetic moment of Fe element in the crystal cell are, 3.626 43μB, 2.678 64 μB, 3.706 17μB. And the energy of crystal cells are -28 540.561 907Ry, -24 268.037 272Ry, -44 106.187 179Ry, These values are in agreement with the experiment values.     

The Effect of Sulfur Segregation on the Adherence of the Thermally-Grown Oxide on NiAl—I: Sulfur Segregation on the Metallic Surface of NiAl(001) Single-Crystals and at NiAl(001)/Al2O3 Interfaces

The aim of this study was to improve the understanding of the deleterious effect of sulfur impurities on the adherence of the thermally-grown oxide on the boundary layer in thermal-barrier-coating systems. In Part I, the sulfur segregation on the free surface of NiAl(001) and at different interfaces between metal and transient alumina scales has been characterized by AES, XPS and LEED. The sulfur diffusion coefficient in the alloy has been determined (D = 0.15 exp(–218,000/RT) cm²/s). It is by three orders of magnitude larger than the nickel and aluminum self-diffusion coefficients. It has also been observed that the sulfur de-segregates upon Al enrichment of the metallic surface. The saturation of the metallic surface with an amorphous alumina layer formed at room temperature blocks the segregation of S. However, in the initial stages of oxidation where the transient -alumina grows by cationic transport and inject vacancies at the interface, S segregates at the interface between the alumina thin films and the metallic substrate.     

Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

The heteropoly complexes K12[Ln(GeW9Mo2O39)2] · nH2O (Ln = La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis, infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis. IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropoly complexes is a square antiprism consisting of eight oxygen atoms of two GeW9Mo2O398-, heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower than that of saturated Keggin structure dodecatungstogermanate.     

Electroreduction of Co(Ⅱ) and La(Ⅲ)in UreaMelt

ＥｌｅｃｔｒｏｒｅｄｕｃｔｉｏｎｏｆＣｏ（Ⅱ）ａｎｄＬａ（Ⅲ）ｉｎＵｒｅａＭｅｌｔＹａｎｇＱｑｉｎ，ＱｉｕＫａｉｒｏｎｇａｎｄＰａｎＳｈｉｊｉａｎ（杨绮琴）（丘开容）（潘仕健）ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＺｈｏｎｇｓｈａｎＵｎｉｃｕｅ...     

ZX001左(右)转向节外壳加工自动线

转向节外壳这种零件的形状很不规则,对这类零件在自动线上加工一般采用随行夹具进行定位夹紧比较合适。但这次我们在设计这条左右转向节外壳加工自动线时大胆地采用了固定夹具直接定位夹紧,经过调试,虽然出现过一些问题,但都得到了解决,并已稳定地连续地加工出一批符合产品技术要求的零件,现在该自动线已交付生产使用。