突泉县和平屯高岭石矿地质特征浅析

通过对研究区内地质特征及含矿蚀变带特征进行分析,内蒙古自治区突泉县和平屯高岭石矿赋存在流纹岩、流纹质凝灰角砾岩石中,研究区共圈出4条高岭土矿体。高岭石矿石呈微细粒结构,块状构造,矿区内矿石类型主要为流纹岩蚀变岩型高岭石矿、流纹质凝灰角砾岩蚀变岩型高岭石矿、花岗斑岩蚀变型岩高岭石矿。经初步分析认为本矿体成因为火山热液蚀变型。

Separation of alumina and silica from metakaolinite by reduction roasting-alkaline leaching process: Effect of CaSO_(4) and CaO

Limestone(CaCO3),which could promote sulfur fixation,was added to coal gangue during roasting in a circulating fluidized bed(CFB)boiler.CaO and CaSO_(4) were the main Ca-bearing minerals while metakaolinite was the major Al-bearing mineral in CFB slag.The effect of CaSO_(4) and CaO on the separation of alumina and silica from metakaolinite by reduction roasting−alkaline leaching process was studied.Results showed that metakaolinite was completely converted into hercynite and silica solid solutions(i.e.,quartz and cristobalite solid solutions)by reduction roasting with hematite.More than 95%of silica in the reduced specimen was removed by alkaline leaching.The addition of CaSO_(4) and CaO remarkably decreased the separation efficiency of alumina and silica in metakaolinite,which could be attributed to the formation of Si-bearing minerals:(1)Fayalite and anorthite were formed during the reduction roasting process;(2)Fayalite was stable while anorthite was converted into sodalite and wollastonite during the alkaline leaching process.This study demonstrates that sulfur in coal gangue should be fixed by treating the exhaust gas instead of controlling the combustion process of CFB to achieve the comprehensive recovery of silica and alumina from the CFB slag.

Synthesis of γ-alkoxy-propylamines and their collecting properties on aluminosilicate minerals

alkoxy-propylamines, C12H25O（CH2）3NH2, C14H29O（CH2）3NH2, C16H33O（CH2）3NH2, C18H37O-（CH2）3NH2 were synthesized from aliphatic alcohol and acrylonitrile. The flotation tests of kaolinite, pyrophyllite and illite were conducted. The flotation mechanisms were explained in view of the structures of reagents and aluminium silicate minerals, zeta potential and Fourier transform infrared spectrum measurements. The results show that the synthesized r-alkoxy-propylamines are more effective than dodecyl amine for flotation of kaolinite, pyrophyllite and illite. For flotation kaolinite and illite, the collecting ability is in the order of C18H37O（CH2）3NH2>C16H33O-（CH2）3NH2>C14H29O（CH2）3NH2>C12H25O（CH2）3NH2, but the r-alkoxy-propylamines types of collectors have almost the same collecting ability on pyrophyllite, which demonstrating that γ-alkoxy-propylamines are new selective collectors for reverse floatation to remove aluminium silicate minerals from bauxite.

Effects of sodium hexmetaphosphate on flotation separation of diaspore and kaolinite

In order to offer high grade concentrate to produce alumina by Bayer, the reverse-flotation technology of bauxite was investigated. The results show that sodium hexmetaphosphate has different depression on the flotation of diaspore and kaolinite. The recoveries of diaspore decrease markedly with the increase of the concentration of sodium hexmetaphosphate with dodecyl-amine as collector. Fourier transform infrared spectra indicate that the absorbance band 875cm -1 of the asymmetric stretching vibration of bridge oxygen P—O—P shifts to 880cm -1 , and the 1264cm -1 of the asymmetric stretching vibration of the bridge PO2 shifts to 1267cm -1 in the diaspore’s spectra. This demonstrates that sodium hexmetaphosphate interacts through bridging PO2 groups with the Al atoms exposed on the diaspore and kaolinite surfaces to form P—O—Al bond. Adsorption measurements also testify that sodium hexmetaphosphate adsorbs easily on the surface of diaspore. The adsorption density of PO-3 on the surface of diaspore is about 4.7×10 -6 mol/m2, while that on the kaolinite is only about 3.5×10 -7 mol/m2 when pH value is 6.

Flotation behavior of four dodecyl tertiary amines as collectors of diaspore and kaolinite

The flotation of diaspore and kaolinite by one of a series of tertiary amines（DRN,DEN,DPN and DBN） was investigated.The tertiary amines show better floating recovery for kaolinite compared to diaspore.The maximum recovery D-value is 45%over a pH range from 3 to 8.FT-IR spectra confirm the presence of hydroxyl groups on the surface of kaolinite and diaspore.Zeta potential measurements show that the mineral surfaces are negatively charged over a wide pH range.Ionization of hydroxyl groups mainly accounts for the surface charging mechanism.The adsorption of tertiary amines onto the mineral surface is due mainly to electrostatic effects and the difference in electrostatic effect between a collector and the two minerals can explain the flotation separation.Inductive electronic and steric effects from the substituent groups result in different collecting powers for the four tertiary amines.

Mineralogy and textural impact on beneficiation of goethitic ore

The effect of mineralogy and texture on the beneficiation of goethitic ores from two different origins is highlighted. Sample A having 54.47% Fe with 8.57% loss of ignition （LOl） indicates the presence of vitreous and ochreous goethite, martite and microplaty hematite as the major minerals. Sample B contains 56.90% Fe with 14.4% LOI. There is a pisolithic laterite containing vitreous and ochreous goethite, quartz, kaolinitic clay and there is no hematite mineral. The liberated minerals in -150 ＋ 100 μm size class are 74% for Sample A and 37% only for Sample B which shows that the Sample A appears to be more amenable to beneficiate. A concentrate of 46.7% with 63.22% Fe could be recovered from Sample A while subjected to gravity separation followed by wet magnetic separation. The Sample B does not respond to gravity and magnetic separation due to its complex mineralogy. However, calcination of the Sample B followed by magnetic separation gives the encouraging results. Thus, anomalous behaviour of the goethite dominated ores in beneficiation is attributed to the different textural and liberation characteristic.

Evolution of kaolinite subgroup minerals and mixed-layer illite/smectite in the Paleogene Damintun Depression in Liaohe Basin of China and its implication for paleotemperature

The oil-rich Damintun Depression is located in the Liaohe Basin, Northeast China, and was formed during the Paleogene. The major oil-producing strata in the depression are mudstone and shale. To explore the burial diagenetic history of the basin and the formation thresholds of hydrocarbons, the characters of the kaolinite subgroup minerals and mixed-layer illite/smectite in the mudstone and the shale are studied by using X-ray diffraction, electron probe, scanning electron microscope, and Fourier infrared spectrum. The kaolinite subgroup consists of kaolinite and halloysite. The kaolinite is flake-like or vermiform-like. The halloysite is in long tubular shape and its length is related to its iron content. A longer tube has lower iron content. The crystallinity of kaolinite is 0.40 ~20, and its degree of order increases from 0.03 to 1.17 with the burial depth. Kaolinite is in disorder when the buried depth is less than or equal to 2479 m, and it is partially ordered when the buried depth is greater than 2479 m. Kaolinite is supposed to turn into dickite when the depth is greater than 2550 m, but low penetrability and low poros- ity of the shale and mudstone prevent such a change. The mixed-layer illite/smectite changes from disorder to order continually as the buried depth increases. Its disorder （RoI/S）, as defined by illite layer content （I%）, is smaller than 50% at depths less than 2550.25 m. Based on Hoffman ＆ Hower＇s model, the paleo-geothermal gradients of 3.37-3.76℃/100 m （3.57℃/100 m on average） can be derived in the Paleocene Damintun Depression, which is significantly higher than the present geothermal gradient （2.9℃00 m）. The threshold depth of the oil formation in the depression is about 2550 m.