scholarly journals The influence of sulfur addition on the hazard-type reaction of ilmenite ores with sulfuric acid

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Maciej Jabłoński ◽  
Krzysztof Lubkowski ◽  
Sandra Tylutka ◽  
Andrzej Ściążko
Keyword(s):  
Sulfuric Acid ◽  
Elemental Sulfur ◽  
Raw Materials ◽  
Thermal Power ◽  
Process Conditions ◽  
Process Safety ◽  
Type Reaction ◽  
Thermokinetic Parameter ◽  
Sulfur Addition ◽  
Titanium Raw Materials

Abstract The paper presents results of thermokinetic investigation of the hazard-type reaction of Norwegian and Australian ilmenite ores with sulfuric acid, modified by the addition of elemental sulfur, to increase the process safety in industrial conditions. In the reactions of both ilmenite ores the addition of sulfur caused a reduction of the thermal power generated in the reaction and a decrease in the value of the thermokinetic parameter ΔTmax/Δτ for almost the whole range of initial concentrations of sulfuric acid. It was also found that the addition of sulfur to the reaction did not negatively affect the degree of ilmenite leaching. The interpretation of the obtained thermokinetic curves allowed to determine safe process conditions for both types of titanium raw materials.

scholarly journals Red Mud as an Additional Source of Titanium Raw Materials

2017 ◽  
Vol 2 (2) ◽  
pp. 150 ◽  
Author(s):  
A.A. Shoppert ◽  
I.V. Loginova
Keyword(s):  
Sulfuric Acid ◽  
Red Mud ◽  
Raw Materials ◽  
Bauxite Residue ◽  
Acid Leaching ◽  
Oxide Content ◽  
Solid Residue ◽  
Second Stage ◽  
Titanium Oxide Content ◽  
Titanium Raw Materials

<p>In this study the extraction of titanium from bauxite residue (red mud) with 2 step acid leaching was proposed. In the first step red mud was leached with diluted hydrochloric acid under stirring to remove the soluble Ca, Na, Al, Si and K at 25 <sup>0</sup>C and pH=3 for 1 hour. The content of iron and titanium in the solid residue increased to 57.7% and 6.4%, respectively. The factors influencing sulfuric acid leaching of the solid residue in the second stage were examined by factorial design. The optimal iron and titanium extraction efficiency was obtained after leaching at 50 oC and L:S ration 20:1 for 90 min when 80 g/L sulfuric acid was used. The titanium oxide content in the concentrate obtained under the optimum conditions amounted to 46.7%. The maximum recovery of titanium in the sulfuric acid solution has not exceeded 6%.</p>

Synthesis of Polyurethane Dendrimers and Transfer Properties of Dye

2013 ◽  
Vol 457-458 ◽  
pp. 65-71
Author(s):  
Jing Ru Jia
Keyword(s):  
Methyl Orange ◽  
Phase Transfer ◽  
Raw Materials ◽  
Toluene Diisocyanate ◽  
Polymerization Process ◽  
Process Conditions ◽  
Addition Polymerization ◽  
Different Temperatures ◽  
The Difference ◽  
Transfer Properties

The polyfunctional organic compounds 2- hydroxymethyl -1,4- butanediol (trihydric alcohol) and toluene diisocyanate -2, 4- diisocyanate (TDI) were taken as the raw materials in this study. A polyurethane dendrimer was synthesized by utilizing the difference in the reaction activity of two isocyanate groups of TDI at different temperatures. The polymerization process conditions were studied. The addition polymerization of para-position NCO groups occurred at 50 °C, and that of ortho NCO groups occurred at 90 °C. According to the structure of the dendrimer synthesized, methyl orange was used as the guest molecule. Consequently, the aqueous methyl orange showed a phase transfer. With the increase of dendrimer concentration, the transfer rate of methyl orange increased.

scholarly journals Reduction of Ash Content in Raw Coal Using Acids and Alkali

2010 ◽  
Vol 7 (4) ◽  
pp. 1254-1257 ◽  
Author(s):  
K. H. Shivaprasad ◽  
M. M. Nagabhushana ◽  
C. Venkataiah
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Coal Sample ◽  
Toxic Elements ◽  
Thermal Power ◽  
Calorific Value ◽  
Ash Content ◽  
Subsequent Removal ◽  
Inorganic Matter ◽  
Leaching Experiments

Ash, an inorganic matter present in coal is amenable for dissolution using suitable reagents. Thus the dissolution of ash and its subsequent removal reduces the release of many toxic elements into the environment by coal based industries. Removal of ash also enhances the calorific value. In the present investigation an attempt has been made to reduce the ash content of raw coal obtained from nearest thermal power by using hydrochloric acid, sulfuric acid and sodium hydroxide. A series of leaching experiments were conducted on coal of different size fractions by varying the parameters like concentration, temperature and time of leaching. The results indicate that it is possible to remove nearly 75% of ash from coal sample by leaching.

scholarly journals New Approach in Research of Quartzes and Quartzites for Ferroalloys and Silicon Production

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 670
Author(s):  
Jaroslav Legemza ◽  
Róbert Findorák ◽  
Branislav Buľko ◽  
Jaroslav Briančin
Keyword(s):  
Raw Materials ◽  
Electricity Consumption ◽  
Process Conditions ◽  
Material Research ◽  
New Approach ◽  
Pure Silicon ◽  
Metallurgical Properties ◽  
Similar Chemical ◽  
The Individual ◽  
Individual Grains

This article deals with material research of selected types of quartz and quartzites in order to determine the priority of their use in the production of ferrosilicon and pure silicon, respectively. The highest quality quartzes and quartzites are commonly used in metallurgy, but not all types of these silicon raw materials are suitable for the production of ferrosilicon and pure silicon, despite their similar chemical composition. Behavior differences can be observed in the process conditions of heating and carbothermic production of ferrosilicon and silicon. These differences depend, in particular, on the nature and content of impurities, and the granularity (lumpiness) and microstructure of individual grains. The research focused primarily on determining the physicochemical and metallurgical properties of silicon raw materials. An integral part of the research was also the creation of a new methodology for determining the reducibility of quartzes (or quartzites), which could be used for real industrial processes and should be very reliable. The results of the laboratory experiments and evaluation of the physicochemical and metallurgical properties of the individual quartzes (or quartzites) are presented in the discussion. Based on comparison of the tested samples’ properties, their priority of use was determined. This research revealed the highest quality in quartzite from Sweden (Dalbo deposit) and Ukraine (Ovruč deposit) and quartz from Slovakia (Švedlár deposit). The use of these raw materials in industrial conditions is expected to result in the achievement of better production parameters, such as higher yield and product quality and lower electricity consumption.

Processing Technogenic Raw Materials-Phosphorus Slags with the Production of Precipitated Nanosilica and Simultaneous Recovery of Valuable Components

2021 ◽  
Vol 316 ◽  
pp. 637-642
Author(s):  
Yelena G. Bochevskaya ◽  
Zaure B. Karshigina ◽  
Aynash S. Sharipova
Keyword(s):  
Specific Surface ◽  
Raw Materials ◽  
Nitric Acid Concentration ◽  
Process Conditions ◽  
Flow Sheet ◽  
Process Duration ◽  
Precipitated Silica ◽  
Component Content ◽  
Slag Processing ◽  
White Soot

The paper provides a flow sheet of the phosphorus slag processing to produce precipitated silica (white soot). The process conditions for opening phosphorus slag at the I stage of leaching have been selected: the nitric acid concentration is 3.5 mol/dm3; the ratio S:L = 1:3.5; the temperature is 60 oС; and the process duration is 1 hour. The parameters of the white soot production II stage have been determined: the HNO3 concentration is 6.5 mol/dm3; the ratio S:L = 1:3.5; the temperature is 50 oС; and the process duration is 1 hour. The temperature effect on the white soot structure and the specific surface have been established. At optimal process parameters, the white soot batches have been obtained with the main SiO2 component content of 88.2 and 90.5 %, and a specific surface of 170 and 182 m2/g, respectively. The through recovery of silicon into a commercial product is 98.0 % of its initial content in slag.

scholarly journals New methods of acid hydrolysis of cellulose and plant raw materials

2021 ◽  
Vol 57 (1) ◽  
pp. 119-128
Author(s):  
V. S. Boltovsky
Keyword(s):  
Acid Hydrolysis ◽  
Plant Biomass ◽  
Raw Materials ◽  
Agricultural Waste ◽  
Feed Additives ◽  
Process Conditions ◽  
Catalytic Systems ◽  
Plant Raw Materials ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Prospects for the development of hydrolysis production are determined by the relevance of industrial use of plant biomass to replace the declining reserves of fossil organic raw materials and increasing demand for ethanol, especially for its use as automobile fuel, protein-containing feed additives that compensate for protein deficiency in feed production, and other products. Based on the review of the research results presented in the scientific literature, the analysis of modern methods of liquid-phase acid hydrolysis of cellulose and various types of plant raw materials, including those that differ from traditional ones, is performed. The main directions of increasing its efficiency through the use of new catalytic systems and process conditions are identified. It is shown that the most promising methods for obtaining monosaccharides in hydrolytic processing of cellulose and microcrystalline cellulose, pentosan-containing agricultural waste and wood, are methods for carrying out the process at elevated and supercritical temperatures (high-temperature hydrolysis), the use of new types of solid-acid catalysts and ionic liquids. 

scholarly journals Extraction of Ta and Nb from a Coltan Bearing Ore by Means of Ammonium Bifluoride Fluorination and Sulfuric Acid Leaching

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1392
Author(s):  
Alidor Shikika ◽  
Francois Zabene ◽  
Fabrice Muvundja ◽  
Mac C. Mugumaoderha ◽  
Julien L. Colaux ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Environmental Benefits ◽  
Process Conditions ◽  
Sulfuric Acid Leaching ◽  
Mechanical Agitation ◽  
Ammonium Bifluoride ◽  
Novel Approach ◽  
Pre Treatment ◽  
Subsequent Acid

A novel approach for Ta and Nb extraction consisting of the pre-treatment of a coltan-bearing ore with an ammonium bifluoride sub-molten salt and subsequent acid leaching has been studied. The effects from ore granulometry, ammonium bifluoride (ABF) to ore mass ratio, temperature and duration of fluorination on the degree of Ta and Nb extraction were examined. The ABF to ore ratio and process temperature were found to have the most pronounced impact on extraction efficiency. The following optimal process conditions were determined: ore granulometric fraction (−75 + 45 µm), ABF-ore (5/1), fluorination temperature (200 °C) and fluorination time (2.5 h). Maintaining these parameters enabled about 94% of Ta and 95% of Nb to be brought into solution during the sulfuric-acid-leaching stage. A comparison of the proposed method with previously reported studies suggests that due to the effects of mechanical agitation and the recirculation of the HF-containing gaseous phase back into the process, the dosage rate of ABF at the fluorination stage could be reduced significantly without sacrificing the overall recovery of Ta and Nb. In such a way, the approach could offer added environmental benefits since release of fluoride-containing effluents into the environment could be limited.

scholarly journals Nitrogen mineralization and microbial activity as influenced by sulfur sources in an alkaline calcareous soil

1970 ◽  
pp. 14-18
Author(s):  
Tufail Shah ◽  
Zahir Shah ◽  
Syed Atizaz Ali Shah ◽  
Nazir Ahmad
Keyword(s):  
Organic Matter ◽  
Sulfuric Acid ◽  
Microbial Activity ◽  
Calcareous Soil ◽  
Bacterial Population ◽  
Elemental Sulfur ◽  
Microbial Population ◽  
Organic Matter Content ◽  
Matter Content ◽  
Fungal Population

A study was performed to check the effects of various sources of sulfur on microbial activity, microbial population, N mineralization and organic matter content in an alkaline calcareous soil by using soil samples collected from Malakandher Farm at 0-20 cm depth, and analyzed for microbial activity, total mineral nitrogen, bacterial and fungal population and organic matter content. The results showed that the rate of CO2 evolution and cumulative CO2 production were higher in soils amended with elemental sulfur followed by sulfuric acid and gypsum treated soils. The microbial activity decreased with incubation period in all treatments, and the microbial population was greatly affected by sulfur sources. Generally, the bacterial population decreased in soils amended with elemental sulfur, but the population was higher in soils amended with gypsum. Bacterial population was suppressed in soils treated with sulfuric acid. However, the fungal population was higher in soils amended with sulfuric acids was less in soil amended with elemental sulfur. The sulfur amendments promoted immobilization of N. The net N immobilized was higher in soil amended with gypsum followed by soils amended with sulfuric acid and elemental sulfur. The percent organic matter was higher in soils amended with gypsum and was decreased compared with that amended with elemental sulfur or sulfuric acid. These results suggested that soil microbiological properties changed with sulfur amendments during laboratory incubation.

scholarly journals CONCOMITANT EXTRACTION PROCESS OF NIOBIUM AT THE TITANIUM TETRACHLORIDE PRODUCTION

2020 ◽  
pp. 173-177
Author(s):  
Т.К. Sarsembekov ◽  
Т.B. Yanko ◽  
S.A. Sidorenko ◽  
M.M. Pylypenko
Keyword(s):  
Phase Transformations ◽  
Nuclear Power ◽  
Titanium Tetrachloride ◽  
Raw Materials ◽  
Extraction Process ◽  
By Products ◽  
Titanium Raw Materials

Development of the fundamentals of a technology for producing niobium by the concomitant extraction in the process of production of titanium tetrachloride from titanium raw materials. The paper provides data on the amount of niobium contained in the feedstock to produce titanium tetrachloride, the distribution of niobium during processing by products and waste. The forms of phase transformations and transitions of niobium during processing are considered. Schemes for processing niobium-containing chloride materials and technologies for their further application for producing alloys for nuclear power are proposed.

scholarly journals Corrosion in CO2 Systems with Impurities Creating Strong Acids

CORROSION ◽  
10.5006/3110 ◽  
2019 ◽  
Vol 75 (11) ◽  
pp. 1307-1314
Author(s):  
Bjørn H. Morland ◽  
Morten Tjelta ◽  
Arne Dugstad ◽  
Gaute Svenningsen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Steel ◽  
Stainless Steels ◽  
Elemental Sulfur ◽  
Experimental Studies ◽  
Visual Observation ◽  
Low Concentrations ◽  
Strong Acids ◽  
Safety And Environment

There are several proposed specifications for CO2 transport regarding how much impurities that can be allowed in the CO2 stream. Many of these specifications are based on health, safety, and environment (HSE) considerations in case of accidental spill, and only limited focus has been on the pipeline integrity. Previous work has demonstrated that many of the impurities that are expected to be present in CO2 captured from flue gasses may react and form corrosive species. The present paper studied impurity reactions and corrosion under simulated transport conditions (25°C and 10 MPa of CO2). An experiment was performed in a transparent autoclave which allowed for in situ visual observation. Chemical reactions between the impurities were observed even at very low concentrations (<100 ppmv). These reactions contributed to the production of nitric and sulfuric acid together with formation of elemental sulfur. Corrosion was observed on coupons of carbon steel, but not on stainless steels. The corrosion rate of carbon steel was low, but the amount of acids and solids (corrosion products) produced cannot be accepted from a pipeline integrity perspective. Further experimental studies are needed to determine specific limits for impurity concentrations in captured CO2 for transport.

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