scholarly journals Studying digestion conditions of Vietnamese monazite with acid sulfuric for the recovery of rare earth elements, thorium and uranium

2021 ◽  
Vol 8 (2) ◽  
pp. 36-42
Author(s):  
Xuan Dinh Luu ◽  
Van Tung Nguyen ◽  
Van Phu Nguyen ◽  
Phuong Thoa Nguyen ◽  
Hoang Mai Tran
Keyword(s):  
Rare Earth ◽  
Acid Treatment ◽  
Optimal Parameters ◽  
High Recovery ◽  
Sulfuric Acid Treatment ◽  
Acid Ratio ◽  
Commercial Source ◽  
Sulfate Process ◽  
Monazite Ore ◽  
Simple Technology

The monazite ore is a commercial source of Th, U and rare earth in Vietnam. There are two methods, which were often applied to decompose monazite ore are alkaline and sulfuric methods. But in Vietnam, sulfuric method is more suitable due to the simple technology. In sulfuric acid treatment its breakdown using sulfate process for recovering of REEs, thorium and uranium. In this study, the parameters such as ore/acid ratios, the digestion temperature and the time of degestion were investigated to determine optimal digestion conditions for high recovery of main ingredients (REEs, Th, U) in monazite ore. The results shown that the optimal parameters for the digestion are ore/acid ratio 1.2:1, digestion temperature - 300oC and time of digestion - 1 hour, the recoveries for REEs, Th and U are namely 90%, 85% and 65%, respectively.

scholarly journals Effect of Sulfuric Acid Treatment and Calcination on Natural Zeolites of Indonesia

2016 ◽  
Vol 28 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Ady Mara ◽  
Karna Wijaya ◽  
Wega Trisunaryati Mudasir
Keyword(s):  
Sulfuric Acid ◽  
Acid Treatment ◽  
Natural Zeolites ◽  
Sulfuric Acid Treatment

Cyclodiene Chemistry. III. Derivative Formation for the Identification of Heptachlor, Heptachlor Epoxide, cis-Chlordane, irans-Chlordane, Dieldrin, and Chromatography

1969 ◽  
Vol 52 (6) ◽  
pp. 1220-1226 ◽  
Author(s):  
Alfred S Y Chau ◽  
W P Cochrane
Keyword(s):  
Sulfuric Acid ◽  
Acid Treatment ◽  
Heptachlor Epoxide ◽  
Improved Method ◽  
Sulfuric Acid Treatment ◽  
Subsequent Conversion ◽  
Concentrated Sulfuric Acid ◽  
Acid Catalyzed ◽  
Cis And Trans ◽  
Feed Samples

Abstract An improved method, involving potassium tert.-butoxide and tert.-butanol treatment followed by acetylation, is described for the similtaneous confirmation of heptachlor, heptachlor epoxide, and cis- and trans-chlordanes in cleaned-up feed samples. Parent pesticide residues can be identified at levels of 0.01 ppm and above. As a confirmative test for dieldrin, the formation of an acetate and subsequent conversion to a “ketone” by acetic anhydride/ sulfuric acid treatment is used. The concentrated sulfuric acid-catalyzed isomerization of endrin is also reported.

Preparation of Low-Sulfur Expanded Graphite with Different Size Particles

2013 ◽  
Vol 652-654 ◽  
pp. 745-748 ◽  
Author(s):  
Chun Yu Wang ◽  
Huan Ran Li ◽  
Chun Lin Qin ◽  
Peng Zhang
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Acid Treatment ◽  
Engineering Application ◽  
Expanded Graphite ◽  
Mixture Ratio ◽  
Sulfuric Acid Treatment ◽  
Low Sulfur

In this paper, results shows that expanded graphite of 128mL/g could be produced under the nitric acid treatment with the optimum mixture ratio of graphite: HNO3: H2O2: KMnO4 being 1(g):6(ml):2(ml):0.02(g), compared with the 145ml/g under the sulfuric acid treatment (graphite: H2SO4: H2O2 =1(g):3(ml):2 (ml)). The sulfur contents are ~0.10wt.% in EG with nitric acid treatment, and ~0.24wt.% in EG with sulfuric acid treatment, respectively. Therefore, the nitric acid treatment EG has little sulfur, which is greatly demanded in engineering application.

Integrated technology of sulfuric acid treatment for eudialyte concentrate

2018 ◽  
pp. 20-27
Author(s):  
V. A. Matveev ◽  
◽  
D. V. Mayorov ◽  
A. V. Solovev ◽  
◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Treatment ◽  
Sulfuric Acid Treatment ◽  
Integrated Technology ◽  
Eudialyte Concentrate
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