Complex Rare Earth Minerals Sulfate Decomposition Techniques Investigation

2019 ◽  
Vol 946 ◽  
pp. 580-584
Author(s):  
K.D. Naumov ◽  
K.A. Karimov ◽  
A.M. Klyushnikov
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Atmospheric Pressure ◽  
Pressure Leaching ◽  
Decomposition Techniques ◽  
The Third ◽  
Iron Aluminum ◽  
Rare Earth Minerals ◽  
Concentrated Sulfuric Acid ◽  
Major Factors

This article presents a study of Tomtor rare earth ore decomposition. This material contains a lot of valuable components such as REE and niobium (mas., %: 12,8 ΣREO (rare earth oxides), 0.039 Sc, 18.4 P2O5, 9.9 Fe, 9.0 Al, 0.24 ThO2, 8.2 Nb2O5). The study aims to find efficient ways of processing this deposit. Technologies using the sulfuric acid as the main reagent to leach are described in this article. Investigation has three trends. The first trend is agitation leaching at low sulfuric acid concentrations, temperatures up to 95 °C and atmospheric pressure. The second trend is pressure leaching at low sulfuric acid concentrations, high temperatures (up to 180 °C) and high pressure. The third trend is high temperature sulfatization with concentrated sulfuric acid at elevated temperature (up to 180 °C) and atmospheric pressure followed by aqueous leaching. The dependence of target components (rare earth elements, scandium, phosphorus) and the impurity (iron, aluminum, thorium) extractions into solution from major factors was studied.

Comparative Study on Removal of Fe, Al and Ca From MG-Si by Acid Leaching

2012 ◽  
Vol 581-582 ◽  
pp. 831-835
Author(s):  
Yi Mai ◽  
Wen Hui Ma ◽  
Ke Qiang Xie ◽  
Tong Wang ◽  
Hu Zhang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Hydrofluoric Acid ◽  
Removal Rate ◽  
Acid Leaching ◽  
Pressure Leaching ◽  
Impurity Removal ◽  
Mixed Acid ◽  
Iron Aluminum ◽  
High Impurity ◽  
Hydrometallurgical Method

In order to find the most effective hydrometallurgical method of removing iron, aluminum and calcium from MG-Si, a variety of acid leaching methods were presented. The research results show that the order of capacity of metallic impurity removal is HF, HCl, HNO3 and H2SO4. The most effective hydrometallurgical method is the leaching by mixed acid with hydrofluoric acid and sulfuric acid. Removal efficiency of hydrochloric acid pressure leaching can improved as the pressure increases. Sulfuric acid and nitric acid even using high pressure leaching cannot obtain high impurity removal rate. The leaching by hydrofluoric acid or mixed acid containing hydrofluoric acid and sulfuric acid is very effective on removal of iron and aluminum, but less effective on calcium.

Materials Flows Analysis on the Beneficiation and Roasting Processes of a Typical Rare Earth Mineral

2016 ◽  
Vol 847 ◽  
pp. 352-357 ◽  
Author(s):  
Chuan Qiu ◽  
Xian Zheng Gong ◽  
Wen Juan Chen ◽  
Zhi Hong Wang ◽  
Feng Gao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Large Scale ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Rare Earth Oxide ◽  
High Pollution ◽  
Concentrated Sulfuric Acid ◽  
Rare Earth Mineral ◽  
Production Preparation

The aim of this paper is to explore material flow analysis, study the resource consumption and environmental impact of the production preparation process of typical rare earth materials. The results showed that in the beneficiation processes, producing one ton of rare earth concentrates (Rare Earth Oxide, REO50%) will also produces 27 tons of iron ore and 21 tons of tailings. The recovery of rare earths is only 16.8%. In roasting processes, roasting one ton (REO50%) of rare earth concentrates will emits 150 ~ 200Kg sulfuric acid mist, 500 ~ 600Kg sulfur dioxide, 30 ~ 40Kg fluoride, 30 ~ 50Kg smoke and1t (containing thorium) radioactive slag, and 1.2 tons of concentrated sulfuric acid should be used. The lower recoveries and large-scale of concentrated sulfuric acid used in roasting processes in rare earth industry are the main reasons lead to high pollution and high emissions.

scholarly journals HYDROMETALLURGICAL NICKEL AND COBALT PRODUCTION FROM LATERITIC ORES: OPTIMIZATION AND COMPARISON OF ATMOSPHERIC PRESSURE LEACHING AND PUG-ROAST-LEACHING PROCESSES

2021 ◽  
Vol 27 (1) ◽  
pp. 17-22
Author(s):  
Serkan Baslayici ◽  
Ozan Coban ◽  
Mehmet Bugdayci ◽  
Mahmut Ercan Acma
Keyword(s):  
Sulfuric Acid ◽  
Atmospheric Pressure ◽  
Chemical Properties ◽  
Acid Leaching ◽  
Pressure Leaching ◽  
Sulfuric Acid Leaching ◽  
Iron Leaching ◽  
Technological Developments ◽  
Cobalt Production ◽  
Leaching Efficiency

Corresponding to the technological developments, production and consumption of nickel have increased greatly over time due to its unique mechanical and chemical properties. Therefore, the production of nickel will always keep its importance. The availability of laterite ores, which are oxide type ores, is 86% of the nickel reserves on the Earth, and the processes used in the production of nickel from sulfide type ores have negative environmental effects. Therefore, recovery of nickel from lateritic ores has become increasingly important in recent years. In this study, the aim was to determine the optimum parameters of nickel and cobalt production from limonite type lateritic nickel ores, which were taken from Manisa Caldag region of Turkey, using atmospheric pressure sulfuric acid leaching and pug-roast-leach process. When the results obtained in these processes were compared, it was found that the Ni leaching efficiency is nearly 8% higher and iron leaching efficiency (contamination) is nearly 4% lower in the pug-roast-leach process. Furthermore, the pug-roast-leach process was completed in 33% lower time compared to the atmospheric pressure sulfuric acid leaching process.

Gallium Arsenide Integrated Circuits Decapsulation Technique Using Mixed Acid Chemistry For Die-Level Failure Analysis

2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria
Keyword(s):  
Gallium Arsenide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Mixed Acid ◽  
Optimum Parameters ◽  
Plastic Package ◽  
Fuming Nitric Acid ◽  
Concentrated Sulfuric Acid

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.

PRODUCTION OF SULFOCATIONITE BY MODIFICATION OF NATURAL COAL WITH CONCENTRATED SULFURIC ACID

2020 ◽  
Vol 3 (441) ◽  
pp. 104-109
Author(s):  
N.A. Bektenov ◽  
◽  
N.C. Murzakassymova ◽  
M.A. Gavrilenko ◽  
А.N. Nurlybayeva ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Concentrated Sulfuric Acid ◽  
Natural Coal

Vapour-liquid equilibrium in the isobutyl formate-isobutyl alcohol and n-butyl formate-isobutyl alcohol systems at atmospheric pressure

1979 ◽  
Vol 44 (12) ◽  
pp. 3501-3508 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Fourth Order ◽  
Atmospheric Pressure ◽  
Isobutyl Alcohol ◽  
Liquid Equilibrium ◽  
The Third

Isobaric vapour-liquid equilibria in the isobutyl formate-isobutyl alcohol and n-butyl formate-isobutyl alcohol systems have been measured at atmospheric pressure. A modified circulation still of the Gillespie type has been used for the measurements. The experimental data have been correlated by means of the third- and fourth-order Margules equations.

Addition of primary alcohols to 3-chlorononafluoro-1,5-hexadiene and perfluoro-1,3,5-hexatriene

1985 ◽  
Vol 50 (8) ◽  
pp. 1714-1726 ◽  
Author(s):  
Václav Dědek ◽  
Igor Linhart ◽  
Milan Kováč
Keyword(s):  
Sulfuric Acid ◽  
Primary Alcohols ◽  
Principal Product ◽  
Allyl Rearrangement ◽  
Concentrated Sulfuric Acid ◽  
Sodium Alkoxide

Sodium alkoxide-catalyzed addition of methanol, ethanol and propanol to 3-chlorononafluoro-1,5-hexadiene (I) proceeds at temperatures -35 °C to 8 °C with allyl rearrangement, affording 1,6-dialkoxy-1,1,2,3,4,4,5,6,6-octafluoro-2,4-hexadiene (V) as the principal product, along with 1,6-dialkoxy-1,2,3,3,4,5,6,6-octafluoro-1,5-diene (VI) and trans-1,6-dialkoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (VII). The ethers Va-Vc consist of the cis,trans- and trans,trans-isomers in about 3 : 1 ratio, whereas the ethers VIa-VIc have trans,trans-configuration. Ethers Vc and VIc react with concentrated sulfuric acid to give dipropyl 2,3,4,5-tetrafluoro-2,4-hexadienedioate (IX) and dipropyl 2,3,4,4,5-pentafluoro-2-hexenedioate (X), respectively, whereas the ether VIIc affords a mixture of propyl 6-propyloxy-2,3,4,4,5,6-heptafluoro-2-hexenoate (XI) and ester X. Addition of methanol to perfluoro-1,3,5-hexatriene (II) affords 1,1,2,3,4,5,6,6-octafluoro-1,6-dimethoxy-3-hexene (XIII) as the principal product.

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