Purification of north Brazilian kaolin by selective flocculation

The main kaolin deposits in north Brazil present are contaminated with colored titanous impurities. Conventional beneficiation processes do not completely remove TiO₂. The difficulty in separation is mainly due to the ultra-fine size of the minerals.This work presents a study of an alternative kaolin purification method based on selective adsorption of soluble polymers. In the process, flocs were generated by interaction of anionic polyacrylamide with titanous impurities and were separated from the kaolin suspension through sedimentation.     

Study on the discontinuance evalution theory of the minerals resource construction item

The period of the minerals resource construction items is very long, which affected largely by the changeable market. The discontinuance evalution theory and content of construction item about the resource used up and economic evalution theories of the invest were brought forward from the two aspects of the resource using value and the income rate.     

硅酸盐矿物的硅酸盐细菌浸出工艺研究

采用5种硅酸盐细菌,对含不同硅酸盐矿物的5种矿样（包括铝土矿原矿和人工混合矿）进行细菌浸矿脱硅摇瓶试验和工艺试验。摇瓶试验表明：5种细菌均能较好地浸出矿样中的硅,但其中JXF-1菌的脱硅效果最好;细菌存活环境和硅酸盐矿物的晶格结构影响浸硅效果。工艺试验表明：连续浸出工艺的细菌浸硅效果明显优于摇瓶试验和半连续浸出工艺,并可将浸出时间缩短4 d;以JXF-F菌为浸矿细菌,以含2%蔗糖的阿什比基质矿物盐培养基为细菌培养液和浸出液,采用连续浸出工艺可从铝土矿原矿和含绿泥石人工混合矿获得铝硅比分别为12.53和17.74的精矿,硅浸出率分别达70.1%和83.6%。     

外刊对中国某些工业矿物出口及合资经营的评论

中国有丰富的工业矿物资源，其中许多在世界上占有重要地位，成为传统的出口商品，尤其是确立以经济建设为中心和扩大与世界各国经济交流的方针实施以来，中国的许多工业矿物及其加工产品不断扩大了进入国际市场的数量，不少工业矿物的出口量在世界同类矿产的贸易中占据了越来越大的份额。与此同时,外国的一些工业矿物公司扩大了与中国同业的合作，在中国建立了一些合作或合资经营项目，这无疑对中外双方都有好处。但是中国工业矿物的出口及对外合作也存在一些问题，应当引起重视。     

辽宁省的孔兹岩系

辽宁省的孔兹岩系主要分布于营口一草河口复向斜南北两翼，具有大致相同的岩石矿物组合、岩石化学及微量元素特征，经历了多期变形变质作用及混合岩化作用，具有同类的非金属矿产。     

Interaction of sodium diisobutyl dithiophosphinate and platinum in aqueous solutions and on sulphide surface

For the noble metal flotation reagents, the authors propose a new test method of selective adsorption on surface of minerals covered with noble metal grains, by using a scanning electron microscope equipped with an X-ray energy-dispersive microanalyzer. Sorption of DTPINa was recorded by SEM and thin layer chromatography on surface of platinum metal grains in the form of a compound identical to the synthesized compound Pt[(iso-C₄H₉)2PS₂]₂. It has been found that interaction of DTPI and platinum ions can run in unheated aqueous solutions at a rate sufficient for flotation. In pH 4–9 range, the rate of platinum DTPI formation is maximal. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 75–84, March–April, 2009.     

Nutrient variation and availability of wheat DDGS,corn DDGS and blend DDGS from bioethanol plants

BACKGROUND: The dramatic increase in bioethanol production in Canada has resulted in millions of tonnes of different types of new co‐products: wheat dried distillers grains with solubles (DDGS), corn DDGS and blend DDGS (e.g. wheat:corn=70:30). There is an urgent need to systematically evaluate the nutritive value of different types of DDGS. Little research has been conducted to determine the magnitude of the differences in nutritive value among wheat DDGS, corn DDGS and blend DDGS and between different bioethanol plants. The objectives of this study were to compare different types of DDGS and different bioethanol plants in terms of: (1) chemical profiles; (2) mineral concentrations of sulfur (S), calcium (Ca) and phosphorus (P); (3) protein and carbohydrate subfractions associated with different degradation rates; (4) digestible component nutrients and energy values; and (5) in situ rumen availability of each DDGS component. RESULTS: The results showed that chemical profiles differed among wheat DDGS, corn DDGS and blend DDGS. Mineral profiles were different among the three types of DDGS with wheat DDGS lower in S (3.9 vs. 7.2 g kg^?1 DM), higher in Ca (1.8 vs. 0.5 g kg^?1 DM) and P (9.1 vs. 7.7 g kg^?1 DM) than corn DDGS, but similar to blend DDGS. Wheat DDGS had the lowest and corn DDGS had the highest energy values (TDN, DE_3X, ME_3X, NEL_3X for dairy; NE_m and NE_g beef cattle) while blend DDGS was in between. Wheat DDGS was lower in the intermediately degradable CP fraction (PB2: 277 vs. 542 g kg^?1 CP) and higher in the rapidly non‐protein degradable fraction (163 vs. 114 g kg^?1 CP) and slowly degradable CP fraction (PB3: 512 vs. 279 g kg^?1 CP) than corn DDGS, but similar to blend DDGS. For carbohydrate subfractions, wheat DDGS was higher in non‐structural carbohydrate fraction (NSC: 483 vs. 184 g kg^?1 CHO), higher in highly degradable free sugars fraction (CA: 359 vs. 91 g kg^?1 CHO), higher in unavailable CHO (CC: 204 vs. 142 g kg^?1 CHO), similar in rapidly degradable CHO fraction (average 108 g kg^?1 CHO), lower in intermediately degradable CHO (CB2: 313 vs. 674 g kg^?1 CHO) than corn DDGS. Wheat DDGS had higher in situ CP degradability and lower NDF degradability than corn DDGS, but similar degradability to blend DDGS. CONCLUSION: Among the three types of DDGS, they differed in chemical characterisation, mineral concentration (S, Ca, P), estimated energy values for both beef and dairy cattle, protein and carbohydrate subfractions, in situ degradability. Bioethanol plants also had significant impact on nutritive value of DDGS. The energy values (DE_3X, ME_3X, NEL_3X, NE_m and NE_g) in wheat DDGS were similar to wheat and corn suggesting wheat DDGS as an alternative to wheat and corn in dairy and beef diets. The energy values (DE_3X, ME_3X, NEL_3X, NE_m and NE_g) in corn DDGS were significantly higher than in corn, indicating that corn DDGS is superior to corn in dairy and beef diets. The energy values (DE_3X, ME_3X, NEL_3X, NE_m and NE_g) in the blend DDGS were higher than that in wheat DDGS but similar to corn DDGS, suggesting blend DDGS as an alternative to corn and superior to wheat and wheat DDGS in dairy and beef diets. Copyright © 2009 Society of Chemical Industry     

铌矿浮选药剂研究进展及生物预处理新思路

根据铌矿浮选药剂的现状,本文综述了脂肪酸类捕收剂、羟肟酸类捕收剂、膦酸类捕收剂及胂酸类捕收剂与铌矿物作用机理。针对铌矿物捕收剂在捕收能力及选择性等方面存在的问题,提出了对开发新型铌矿物捕收剂的要求。总结了铌矿浮选调整剂的研究现状,指出了脉石矿物有效抑制剂研究是铌矿浮选调整剂研究的重点。对于铌矿的浮选,目前大多数研究是采用传统的化学药剂来改变铌矿物与其它矿物间的可浮性差异,效果仍不理想。本文通过分析含铌矿物的特点,提出了铌矿生物预处理新思路。应用生物预处理对目的矿物和脉石矿物表面进行改性,达到扩大目的矿物与脉石矿物可浮性差异的目的,以实现铌矿物的高效回收。     

A design of experiments investigation into dry separation using a Knelson Concentrator

Enhanced gravity, or centrifugal, separators have revolutionised gold processing over the past decades, significantly increasing the recovery of fine (−100 μm) free gold. One of the main drawbacks of centrifugal gravity concentrators is the large volume of water required (even if it is all recycled). With water becoming an ever increasingly important “commodity”, reducing this is of importance both from an environmental and a monetary point of view. This work investigated operating a laboratory scale Knelson Concentrator with a dry feed and using air as the fluidising medium. The feed used was a synthetic mixture of tungsten and quartz, used to mimic a gold ore. The response surface method and central composite design techniques were used to design the experiments and to model the results, with the experimental variables being the bowl speed (G-Level), air fluidising pressure and the feed rate. The models corresponded well to the experimental results, indicating that for this experimental setup, the optimal conditions were a bowl G-Level of 40 G, a feed rate of 220 g/min and an air fluidising pressure of 8 psi.