scholarly journals Arsenic in Chemical and Metallurgical Conversions of Copper-zinc Concentrates

2020 ◽  
Author(s):  
Evgeny Nikolaevich Selivanov ◽  
Dmitry Olegovich Novikov ◽  
Vyacheslav Vasi- Lyevich Belyaev ◽  
Gennady Veniaminovich Skopov
Keyword(s):  
Sulfuric Acid ◽  
Electrostatic Precipitator ◽  
Metallic Copper ◽  
Gas Treatment ◽  
Sulfuric Acid Production ◽  
Keywords Arsenic ◽  
Copper Zinc ◽  
Sulfide Concentrates ◽  
Impurity Elements

Due to the deterioration of the quality of obtained sulfide-copper concentrates, arsenic circulates and accumulates in the intermediate products, which reduces the quality of the metal and associated product – sulfuric acid. A method of estimation the distribution of impurity elements can be created using the recycling of sulfide concentrates by various technologies (including autogenous smelting, matte conversion and flotation of slags). This technique is based on solving balance equations for iron, copper and arsenic with known compositions of the resulting products. The obtained data were used to assess of the extraction of arsenic into produce outputs (slag, matte, dust, etc.). In this study, the concentration of arsenic in the dust of metallurgical processes and sludge for cleaning acid solutions is confirmed. The increased temperature in the electrostatic precipitator of gas purification of autogenous processes lead to a partial transition of arsenic into the gas stream directed to the sulfuric acid production. It is possible to regulate the fraction of transition of arsenic to dust and sulfuric acid while changing the operating temperature in the electrostatic precipitator. To a lesser extent arsenic is concentrated in the tails of flotation of slag (11.7%) and metallic copper (2.9%). These data are useful for substantiating measures for the wastes recycling and improvement of the ecological environment in the enterprise operating districts. Keywords: arsenic, autogenous melting, matte conversion, slag flotation, purified gas treatment, distribution, dust, sludge

scholarly journals SISTEM PENINGKATAN PRODUKTIVITAS MESIN PRODUKSI ASAM SULFAT DENGAN METODA TOTAL PRODUCTIVE MAINTENANCE

2015 ◽  
Vol 5 (3) ◽  
Author(s):  
Tri Sutrisno
Keyword(s):  
Sulfuric Acid ◽  
Acid Production ◽  
Continuous Process ◽  
Treatment System ◽  
Total Productive Maintenance ◽  
Sulfuric Acid Production ◽  
Improved Performance ◽  
Three Components

<p>Sulfuric acid production is a continuous process. With the process running constantly then the condition<br />of machinery should be maintained properly so as not frequent downtime. Downtime will result in<br />decreased production achievement and damage the quality of the product.<br />To overcome this designed a treatment system using the concept of TPM in a corporate<br />environment, which is expected to bring harmony between the operator as to the implementation of the<br />production engineer and production planner’s parties as well as the maintenance. The concept of total<br />productive maintenance is one way for the company's improved performance is more stable. The<br />concept of total productive maintenance consists of three important components of a total approach,<br />efforts productive, and maintenance. Of the three components can be explained using the concept of<br />Overall Equipment Effectiveness and autonomous maintenance.</p>

Change of quality indexes of premixes in the storage process

2020 ◽  
pp. 105-112
Author(s):  
Oksana Bitlian ◽  
Oksana Kravchenko ◽  
Tetiana Kodak ◽  
Andrii Onyshchenko ◽  
Tetiana Konks
Keyword(s):  
Raw Materials ◽  
Storage Process ◽  
Important Place ◽  
Inappropriate Use ◽  
Chemical Structures ◽  
Copper Zinc ◽  
Qualitative Responses ◽  
Chelating Compounds ◽  
Quality Indexes

The analysis of literature sources shows that the type and material from which the packaging is made has an important place in the system of factors which influence on the storage of feed products and also prevents reducing the quality of raw materials and finished products. Therefore, the purpose of our research is the technological justification of changing the quality indexes of premix samples with salts of trace elements of different chemical nature in the process of storage. For the solution of the tasks, common zootechnical and statistical methods of the research were used. The use of premixes in feeding pigs is based on the fact that they should be used taking into account the biogeochemical properties of the region for which they are calculated. Foods depending on regional properties have a special biochemical composition and excess or lack of individual substances should be offset by the composition of premix. Ignoring this provision necessarily leads to the inappropriate use of BAR, the misbalance of the diet in relation to the physiological needs and inefficiency of the industry. In turn, it requires the purchase and conservation of products for the period of use. Various chemical structures and structures of BAR during the storage process react differently and change qualitative indexes, which leads to a decrease in the productive activity of active substances. It was determined that the humidity of premixes varied within the limits of 12.0-13.0 %, which exceeded the normative, but was not critical, the highest acidity had premix with sulfuric acid salts (6.9 units), the least - premix with lysates (5.7 unit). According to the results of the study, positive qualitative responses were found for the presence of vitamins A, D and B2, macro- and micronutrients: potassium, magnesium, copper, zinc, cobalt, iodine. The above facts of changes in the properties of premixes in the process of storage must be taken into account when providing technological bases for feeding pigs in order to obtain high gains and the quality of manufactured products. Key words: premix, micro-and macro elements, combined fodders, fodder mixes, chelating compounds, feeding, using, pigs' livestock.

Effect of Chlorine Dioxide Gas Treatment on Surface Sterilization of Grape

2011 ◽  
Vol 236-238 ◽  
pp. 2939-2944 ◽  
Author(s):  
Ri Ya Jin ◽  
Shuang Qi Hu ◽  
Zhi Chao Chi
Keyword(s):  
Chlorine Dioxide ◽  
Treatment Time ◽  
Reducing Sugar ◽  
Gas Treatment ◽  
Surface Sterilization ◽  
Log Reduction ◽  
Chlorine Dioxide Gas ◽  
Spoilage Bacteria ◽  
Effect Of Chlorine

Experiments were conducted to investigate the effect of concentration and duration of chlorine dioxide gas treatment on Surface sterilization of grape at 25°C. The results showed that the values of inactivate bacterial log reduction ofBotrytis cinerea,Penicilliumandalternariaincreased with the increasing of ClO2gas concentrations and treatment time. When the concentrations and treatment time was about 10 mg/m3and 30 minutes, respectively, more than 4 log reduction was obtained for the three spoilage bacteria on grape surface. Furthermore, the effect of chlorine dioxide gas treatment on quality of grape was investigated. It was found that the contents of vitamin C (Vc) and reducing sugar (RS) in grape also increased compared with grape without ClO2gas treatment.

Climate impact of an optimised gas treatment on old landfills

2022 ◽  
pp. 0734242X2110701
Author(s):  
Roland Berger ◽  
Joachim Lehner
Keyword(s):  
New Technology ◽  
Landfill Gas ◽  
Calorific Value ◽  
Climate Impact ◽  
Treatment Technology ◽  
Gas Treatment ◽  
Treatment Measures ◽  
Established Fact ◽  
New Treatment

It is a well-established fact that the quality and quantity of landfill gas (LFG) start declining after a landfill is closed to further waste intake. Conventional gas treatment and utilisation systems such as flares and gas-driven engines require a certain quality of LFG: specifically, a sufficient methane concentration. Various measures are utilised to maintain the necessary quality of LFG, including a turn-down of gas extraction rates and a shutdown of low-quality gas wells, resulting in a decline of LFG production. This, however, does not have to be the case. The low calorific value (LCV) LFG capture and treatment technology developed by e-flox and referred to in this article as ‘LCV LFG System’ can significantly increase the collection rate and the amount of treated methane in an old landfill. This article introduces such new treatment measures, describes gas capture calculation methodologies and presents actual results based on a medium-sized landfill in Germany. The study demonstrates, among other things, that the LCV LFG system can reduce the CO2 avoidance costs to roughly 10 €/tCO2eq. We present this new technology as a quick and straightforward measure of dealing with the climate issues related to methane emissions of old landfills.

Experimental Evaluation of the Chill Casting Method for the Fabrication of LM-25 Aluminum Alloy-Borosilicate Glass (p) Composites

2017 ◽  
Vol 748 ◽  
pp. 69-73 ◽  
Author(s):  
Anupama Hiremath ◽  
Joel Hemanth
Keyword(s):  
Aluminum Alloy ◽  
Borosilicate Glass ◽  
Metallic Copper ◽  
Matrix Material ◽  
Weight Percent ◽  
Grain Structure ◽  
Matrix Composites ◽  
Hardness Tests ◽  
Result Analysis

The paper investigates the novelty of application of end chills in fabricating Aluminum alloy metal matrix composites. An effort has also been made to evaluate the effect of chill material on the soundness of the castings obtained. The required composites were prepared using LM-25 Aluminum alloy as matrix material in which different weight percent of Borosilicate glass particles were added ranging from 3 wt.% to 12 wt.%. The variation in weight percent was brought about in steps of 3%. The fabrication of the composites was carried out in sand molds by incorporating two metallic (copper and Steel) and two non-metallic (Graphite and Silicon carbide) end chills. The specimens for strength and hardness tests were prepared as per ASTM standards and the specimens were drawn from near chill-end as well as from farther away from chill end. The microstructure of the specimens reveal a refined grain structure proving the sound quality of the castings. The result analysis also leads to the conclusion that metallic chills are more beneficial as compared to non-metallic chills for obtaining a good quality composites. Copper chill with a high volumetric heat capacity proved to be the best chill material amongst the others.

scholarly journals A Study on the Characteristics of Chemical Accidents and Reduction of Accidents in Jeollabuk-do

2020 ◽  
Vol 34 (2) ◽  
pp. 49-53
Author(s):  
Jae-Uk Jeong ◽  
Chong-Eun Park
Keyword(s):  
Adverse Reaction ◽  
Sulfuric Acid ◽  
Silicon Tetrachloride ◽  
Government Support ◽  
Safety Education ◽  
Chemical Accidents ◽  
Vehicle Accidents ◽  
Transport Vehicle ◽  
And Training

This study aimed to identify the characteristics of 40 chemical accidents that occurred in Jeollabuk-do from 2004 to 2019. During this time, there were 2.5 accidents per year on average in the province; their types were classified as spill/leak, fire, explosion, adverse reaction, and complex. There were 34 leaks and six explosions, and they are categorized as follows: 12 by worker error, 16 from facility defects, and 12 by transport vehicle accidents. The substances involved in these accidents were ammonia (15%), sulfuric acid (12.5%), and silicon tetrachloride (7.5%). Notably, the rate of chemical accidents (75%) is the highest during spring and summer. In order to reduce chemical accidents, first, there should be compliance with the relevant laws. Second, the quality of safety education and training of workers should be improved. Finally, valuable government support is also necessary to improve facilities.

Water Quality of Lake Iskanderkul and Its Tributaries

2020 ◽  
Vol 6 (2) ◽  
pp. 79-88
Author(s):  
Z.O. Normakhmedova ◽  
◽  
A.V. Mitusov
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Chemical Composition ◽  
Fish Farming ◽  
Natural Phenomena ◽  
Change Dynamics ◽  
Chemical Composition Of Water ◽  
Study Results ◽  
Copper Zinc

This article presents the study results of the change dynamics in the chemical composition of water in Lake Iskanderkul and the rivers flowing into it, as well as the comparison of water quality in the water bodies of the Iskanderkul Basin and several mid-stream tributaries of the Zarafshan River. It was established that the chemical composition of water in Lake Iskanderkul and its tributaries meets the requirements of the corresponding state standard (GOST 2874-82 “Drinking Water”). However, in terms of dissolved oxygen, copper, zinc, lead and iron the water in Lake Iskanderkul does not satisfy fish farming requirements. The main water pollution sources in the area include such natural phenomena as floods, avalanches, mudslides, and rock dissolution.

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