scholarly journals The effect of Fe3+ ions on the electrochemical behaviour of ocean manganese nodule reduction leaching in sulphuric acid solution

RSC Advances ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 1121-1129
Author(s):  
Jinxing Kang ◽  
Yayun Wang ◽  
Yunfei Qiu
Keyword(s):  
Acid Solution ◽  
Sulphuric Acid ◽  
Electrochemical Behaviour ◽  
Manganese Nodule ◽  
Sulphuric Acid Solution ◽  
Acid Solutions ◽  
Reductive Leaching

The effect of Fe3+ ions on the ocean manganese nodule reductive leaching in imitated sulphuric acid solutions was investigated.

THE ABSORPTION AND FLUORESCENCE PROPERTIES, IN THE VISIBLE SPECTRAL REGION, OF CERTAIN STEROIDS IN SULPHURIC ACID SOLUTIONS

1952 ◽  
Vol 30 (3) ◽  
pp. 213-230
Author(s):  
J. H. Linford ◽  
O. Bernice Paulson
Keyword(s):  
Acid Solution ◽  
Sulphuric Acid ◽  
Testosterone Propionate ◽  
Sulphuric Acid Solution ◽  
Visible Spectral Region ◽  
Hydroxyl Group ◽  
Acid Solutions ◽  
Steroid Molecule ◽  
Desoxycorticosterone Acetate ◽  
Colored Compound

The absorption and fluorescence of steroids dissolved in concentrated sulphuric acid, and the changes in these properties on adding ethanol to the concentrated acid solutions, have been examined for: cholesterol, pregnandiol, α-estradiol, dehydroisoandrosterone (D.H.A.), dehydroisoandrosterone acetate, desoxycorticosterone acetate, (D.O.C.A.), testosterone propionate, and progesterone. At 57° C. or less, in concentrated sulphuric acid solution a colored compound was formed only if an hydroxyl group was present in the steroid molecule; the keto group formed a colored compound with sulphuric acid only in the presence of a hydroxyl group in the same steroid molecule. As the concentrated sulphuric acid solutions were diluted with alcohol, absorption maxima appeared which were characteristic of specific hydroxyl and keto groups. Irradiation of the solutions by light of the spectral regions corresponding to the absorption maxima produced related fluorescent bands.

The oxidations of DL-atrolactic and 2-hydroxyisobutyric acids by cerium(IV) in sulphuric acid solutions

1970 ◽  
Vol 23 (4) ◽  
pp. 757 ◽  
Author(s):  
VK Grover ◽  
YK Gupta
Keyword(s):  
Complex Formation ◽  
Acid Solution ◽  
Organic Acid ◽  
Sulphuric Acid ◽  
Rate Constant ◽  
Sulphuric Acid Solution ◽  
Acid Solutions ◽  
Rate Law ◽  
Hydroxyisobutyric Acid

Oxidations of DL-atrolactic and 2-hydroxyisobutyric acids by cerium(IV) in sulphuric acid solution occur in accordance with the empirical rate law: (see equation in article) where k1 is a complex rate constant and A is an unspecified constant. Spectrophotometric results suggest complex formation between cerium(1v) and the organic acid, but no kinetic evidence was obtained. Manganese(11) catalyses the reactions. DL-Atrolactic acid is more reactive than 2-hydroxyisobutyric acid. The products of oxidations were acetophenone and acetone respectively.

scholarly journals TINJAUAN PENAMBAHAN ADITIF MINERAL ABU TERBANG TERHADAP KETAHANAN BETON PADA LINGKUNGAN AGRESI SULFAT

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Ernawati Sri Sunarsih
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Sulphuric Acid Solution ◽  
Strength Degradation ◽  
Acid Solutions ◽  
Normal Concrete ◽  
Mineral Additive ◽  
Compressive Strength Of Concrete

<p><em>The research aims to determine ( 1) the increase of compressive strength of concrete with addition of fly ash to be compared to normal concrete ( 2) the resistant of normal concrete and also concrete with fly ash mineral additive in 2%, 5% and 7% sulphuric acid solutions, and ( 3) the resitant of concrete with fly ash mineral additive with the increase of concentration of sulphuric acid solution in comparing normal concrete.</em></p><p><em>The method employed in this research was experimental method, by preparing the test object constituting the concrete cylinder with </em><em>Æ</em><em> 150 mm and 300 mm height for the compressive strength test. With the percentage of fly ash addition are 0%, 20%, 30% and 40% from requirement cement and qualities of designed concrete is 22,5 MPa. Amount of object test to the each condition is 4. To know concrete resistant in sulphate aggression environment, hence conducted by immersied of concrete in sulphuric acid solutions with concentration 2%, 5% and 7% during 30 days.</em></p><p><em>From the research, it can be found that: ( 1) the addition of fly ash into fresh concrete will improve compressive strength of concrete. At addition fly ash 20% from requirement cement, compressive strength of  concrete increase 23,39%. For the addition of fly ash 30% and 40%, the increase of compressive strength concrete were 21,54 % and 0,31%. While in optimum percentage of fly ash addition is 23,46% (2) the immersied concrete in sulphuric acid solution result degradation compressive strength of concrete. At the same concentration of sulphuric acid solution, concrete with fly ash additive mineral have resistant which is better to be compared to normal concrete. This seen [at] percentage of compressive strength degradation of fly ash concrete which is smaller to be compared to normal concrete. Equally the percentage of compressive strength degradation inversely proportional with the percentage of fly ash addition ( 3) the increase of concentration of sulphuric acid solution will be result of aggression that happened at ever greater. If compared to normal concrete, concrete with fly ash in the reality more effective if used at high concentration of sulphuric acid solution. This matter can be seen from difference of percentage of compressive strength degradation ever greater at the height of concentration of sulphuric acid solution.</em></p>

Effect of hydride formation on corrosion behaviour of Zr–1%Nb alloy in sulphuric acid solution

2016 ◽  
Vol 51 (3) ◽  
pp. 195-200 ◽  
Author(s):  
I. M. Gharatloo ◽  
A. N. Golikand ◽  
M. B. Fathi ◽  
R. S. Gharabagh ◽  
I. Hasanzadeh
Keyword(s):  
Acid Solution ◽  
Sulphuric Acid ◽  
Corrosion Behaviour ◽  
Sulphuric Acid Solution ◽  
Hydride Formation

Development and Research of Copper Covering for Intensification of Cold Stamping of Products from Stainless Steels

2021 ◽  
Vol 316 ◽  
pp. 809-813
Author(s):  
Vladimir V. Karzhavin ◽  
Lev V. Maltsev ◽  
Viktoriya V. Bakina
Keyword(s):  
High Temperature ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Stainless Steels ◽  
Diffusion Zone ◽  
Pure Copper ◽  
Sulphuric Acid Solution ◽  
Fused Salts ◽  
Substitution Type ◽  
Cold Stamping

The copper covering put in fused salts of chlorides at temperature of 450-500cC and preventing scuffs on the surface of steel of type 12X18H10T at cold stamping of case products and fixture was investigated. Metallurgical surveys have shown: 1) except cover zone and zone of base metal there is also transition zone, representing substitution type of solution; 2) in the course of application there is superficial alloying, due to penetration of atoms of copper deep into metal and diffusions of doping steel elements in coating material under the influence of melts's high temperature. The schedule of change of concentration of copper in diffusion zone allows to conclude that the copper covering consists not of pure copper, and that the alloy contains only 94% of copper; other 6% represent the chrome and the titanium diffusing in copper covering. It is established also that, despite strong cohesion with basis, the covering is completely removed from surface of the stamping details being dissolved in standard sulphuric acid solution.

Influence of chelating agents on the tribocorrosion of tungsten in sulphuric acid solution

2011 ◽  
Vol 56 (20) ◽  
pp. 7131-7140 ◽  
Author(s):  
J. Stojadinovic ◽  
D. Bouvet ◽  
M. Declercq ◽  
S. Mischler
Keyword(s):  
Acid Solution ◽  
Sulphuric Acid ◽  
Chelating Agents ◽  
Sulphuric Acid Solution
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