scholarly journals Kajian Awal Produksi Fero Sulfat dari Slag Nikel Melalui Proses Pelindian Menggunakan Asam Sulfat

2020 ◽  
Vol 18 (1) ◽  
pp. 31-38
Author(s):  
Asep Nurohmat Majalis ◽  
Nur Vita Permatasari ◽  
Yeni Novitasari ◽  
Noviarso Wicaksono ◽  
Dedi Armin ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Mineral Composition ◽  
Acid Concentration ◽  
Ferrous Sulfate ◽  
Government Regulation ◽  
Sulfate Production ◽  
Iron Metal ◽  
Toxic Materials ◽  
Mining Wastewater ◽  
Preliminary Study

AbstractNickel production with a pyrometallurgical process produces slag as a side product. Base on government regulation no.101 of 2014, nickel slag included in hazardous and toxic materials from specific sources with hazard category 2. The study of the use of nickel slag is quite interesting because chemically still contains valuable minerals and metals, and iron metal contained in nickel slag is the most dominant. A preliminary study of ferrous sulfate production from nickel slag was carried out which has the potential to be used for the treatment of nickel ore mining wastewater. The stages have been taken are characterization and leaching of nickel slag using sulfuric acid. The main mineral composition of nickel slag are fayalite, magnetite, and cristobalite with the dominant elements are Fe, O, Si, S, Mg, Ni, and Cu. The content of Fe, Ni, Co and Cu in nickel slag samples are 37%, 0.479%, 0.361%, and 0.0843% respectively. Nickel slag morphology is an irregular polygon and the surface is smooth and dense. Nickel slag leaching carried out on the ratio of the volume of the leachate to the weight of the slag is 1000 ml/500 g, acid concentration are 0.2, 0.25, 0.3 and 0.35 and leaching time is 5 days had successfully dissolved Fe(II) from nickel slag 2790, 1940, 4180 and 5160 mg/L respectivelyKeywords: nickel slag, ferrous sulfate, characterization, leachingAbstrakProduksi nikel dengan proses pirometalurgi menghasilkan hasil samping yaitu slag. Slag nikel berdasarkan Peraturan Pemerintah No.101 tahun 2014 termasuk limbah bahan berbahaya dan beracun dari sumber spesifik khusus dengan kategori bahaya 2. Kajian pemanfaatan slag nikel cukup menarik dilakukan karena secara kimia slag nikel masih mengandung mineral dan logam-logam yang berharga, dan kandungan logam besi di dalam slag nikel adalah yang paling dominan. Telah dilakukan kajian awal produksi fero sulfat dari slag yang berpotensi dapat dimanfaatkan untuk proses pengolahan air limbah pertambangan bijih nikel. Tahapan yang dilakukan yaitu karakterisasi dan pelindian slag nikel menggunakan asam sulfat. Komposisi mineral utama slag nikel adalah fayalit, magnetit dan kristobalit dengan kandungan unsur dominan Fe, O, Si, S, Mg, Ni, dan Cu. Kandungan logam Fe, Ni, Co, dan Cu dalam sampel slag nikel secara berturut-turut yaitu 37%, 0,479%, 0,361%, dan 0,0843%. Morfologi slag nikel adalah poligon tidak beraturan dan permukaannya halus serta padat. Pelindian slag nikel yang dilakukan pada perbandingan volume pelindi terhadap berat slag nikel yaitu 1000 ml/500 gram, konsentrasi asam sulfat secara berturut-turut 0,2; 0,25; 0,3 dan 0,35 mol/L dan waktu pelindian 5 hari telah berhasil melarutkan Fe(II) dari slag nikel secara berturut-turut 2790; 1940; 4180 dan 5160 mg/L.Kata kunci: slag nikel, fero sulfat, karakterisasi, pelindian

scholarly journals Preliminary Study on Gold Recovery from High Grade E-Waste by Thiourea Leaching and Electrowinning

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Nicolò Maria Ippolito ◽  
Ionela Birloaga ◽  
Francesco Ferella ◽  
Marcello Centofanti ◽  
Francesco Vegliò
Keyword(s):  
Sulfuric Acid ◽  
Leach Solution ◽  
High Grade ◽  
Gold Dissolution ◽  
Plastic Part ◽  
The Third ◽  
Current Consumption ◽  
Different Types ◽  
Preliminary Study ◽  
A Current

The present paper is focused on the extraction of gold from high-grade e-waste, i.e., spent electronic connectors and plates, by leaching and electrowinning. These connectors are usually made up of an alloy covered by a layer of gold; sometimes, in some of them, a plastic part is also present. The applied leaching system consisted of an acid solution of diluted sulfuric acid (0.2 mol/L) with thiourea (20 g/L) as a reagent and ferric sulfate (21.8 g/L) as an oxidant. This system was applied on three different high-grade e-waste, namely: (1) Connectors with the partial gold-plated surface (Au concentration—1139 mg/kg); (2) different types of connectors with some of which with completely gold-plated surface (Au concentration—590 mg/kg); and (3) connectors and plates with the completely gold-plated surface (Au concentration—7900 mg/kg). Gold dissolution yields of 52, 94, and 49% were achieved from the first, second, and third samples, respectively. About 95% of Au recovery was achieved after 1.5 h of electrowinning at a current efficiency of only 4.06% and current consumption of 3.02 kWh/kg of Au from the leach solution of the third sample.

scholarly journals Corrosion Behavior of AA 1100 Anodized in Gallic-Sulfuric Acid Solution

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 405
Author(s):  
Marlon L. Mopon ◽  
Jayson S. Garcia ◽  
Dexter M. Manguerra ◽  
Cyril John C. Narisma
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Gallic Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Solution ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Anodized Aluminum ◽  
The Common

Sulfuric acid anodization is one of the common methods used to improve corrosion resistance of aluminum alloys. Organic acids can be added to the sulfuric acid electrolyte in order to improve the properties of the anodized aluminum produced. In this study, the use of gallic acid as an additive to the sulfuric acid anodization of AA1100 was explored. The effect of varying anodization current density and gallic acid concentration on the properties of anodized aluminum samples was observed using electrochemical impedance spectroscopy, linear polarization, and scanning electron microscopy. It was observed that the corrosion resistance of samples anodized in gallic-sulfuric acid solution at 10 mA·cm−2 is lower than samples anodized in sulfuric acid. It was also observed that higher anodization current density can lead to lower corrosion resistances for aluminum samples anodized in gallic-sulfuric acid solution. However, samples anodized at 5 mA·cm−2 and at a gallic acid concentration of 5 g·L−1 showed better corrosion performance than the samples anodized in sulfuric acid only. This suggests that the use of low amounts of gallic acid as an additive for sulfuric acid anodization can lead to better corrosion resistances for anodized aluminum.

scholarly journals Release of reducing sugars from water hyacinth by thermochemical and enzymatic hydrolysis

2021 ◽  
Vol 6 (1) ◽  
pp. 156-164
Author(s):  
Jessica E. Guzmán-Pérez ◽  
◽  
Oscar J. Salinas-Luna ◽  
Ernesto Favela-Torres ◽  
Nohemi López-Ramírez ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Acid Concentration ◽  
Water Hyacinth ◽  
Dry Matter ◽  
Eichhornia Crassipes ◽  
Reducing Sugars ◽  
Sulfuric Acid Concentration ◽  
Raw Material ◽  
Thermochemical Pretreatment

Water hyacinth (Eichhornia crassipes) is considered a pernicious herb in many parts of the world due to its rapid growth. However, for its high content of cellulose and hemicellulose, it could be considered as raw material to produce fermentable sugars. In this work, the effect of sulfuric acid concentration by thermochemical pretreatment and enzymatic hydrolysis on the release of sugars from water hyacinth was evaluated. Initially, the effect of the sulfuric acid concentration from 1.5 to 9% at 120 ºC was evaluated. With 1.5%, the release of reducing sugars was 160 milligrams of reducing sugars per gram of dry matter (mg red-sug/g dm). After the thermochemical pretreatment, the enzymatic hydrolysis with the cellulase complex (NS22086) allowed obtaining a reducing sugars concentration up to 317 mg red-sug/g dm. These thermochemical and enzymatic approaches to recover reducing sugars from water hyacinth is promising and should be evaluated for bioprocess using reducing sugars as the main source of carbon, such as bioethanol production.

scholarly journals The Effect of Electronic Medical Record Adaptation on Reported Medication Errors in Peripartum Care Areas

2017 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Cellulose Hydrolysis ◽  
Colloidal Dispersions ◽  
Degree Of Polymerization ◽  
Degree Of Crystallinity ◽  
Minimum Level ◽  
Hydrolysis Temperature ◽  
Hydrolysis Conditions ◽  
Negative Zeta Potential

Relationship between concentration of sulfuric acid (C) and temperature (T) required for the cellulose hydrolysis to prepare nanocrystalline cellulose particles (NCP has been studied in this paper. The experiments showed that there is a linear C and T superposition exists, namely: C= Co - n T. The higher the acid concentration, the lower the hydrolysis temperature should be used, and vice versa. The minimum level of acid concentration that can be used for production of CNP is 40 wt. % at optimal temperature of 80o C. If temperature or acid concentration is lower, there is a tendency to form of microparticles. On the other hand, at higher hydrolysis temperatures, carbonized CNP with decreased yield are obtained. The rod-like crystalline nanoparticles of cellulose produced at optimal hydrolysis conditions (C=40 wt. %, T=80o C) have average sizes of 150 x 15 nm, degree of crystallinity of 75- 77% and degree of polymerization of 130-150. The nanoparticles form stable colloidal dispersions in water due to Brownian motion and negative Zeta potential imparting to these particles the mutual electrostatic repulsion. Estimated calculations have also shown that decrease in the concentration of sulfuric acid from 60 to 40 wt. % at production of CNP is economically advantageous despite increase in hydrolysis temperature from 45 to 80o C.

scholarly journals Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 565 ◽  
Author(s):  
Norman Toro ◽  
Nelson Herrera ◽  
Jonathan Castillo ◽  
Cynthia Torres ◽  
Rossana Sepúlveda
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Room Temperature ◽  
Sulfuric Acid Concentration ◽  
Extraction Rate ◽  
Molar Ratio ◽  
Independent Variables ◽  
Initial Investigation ◽  
Optimization Methodology

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.

Rate of lactamization of benzylstrychnine in acid solution

1984 ◽  
Vol 62 (1) ◽  
pp. 144-146 ◽  
Author(s):  
John T. Edward ◽  
Sin Cheong Wong ◽  
Robert A. McClelland
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Acid Concentration ◽  
Amino Group ◽  
Cage Structure ◽  
Basic Formula

The rate of lactamization of benzylstrychnine in aqueous solution at 25 °C increases with acid concentration up to 5–10% sulfuric acid, and thereafter decreases. The maximum can be explained by taking account of the extent of protonation of the aromatic amino group with increasing acid concentration. This amino group is unusually weakly basic [Formula: see text], perhaps because it is locked in an extremely rigid cage structure which opposes the rehybridization of N which must take place when it is protonated.

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