scholarly journals MlNERALOGICAL STUDY AND PROPERTIES OF MAGNESIA REFRACTORIES DERIVED FROM EVIAN MAGNESITE

2004 ◽  
Vol 36 (1) ◽  
pp. 97 ◽  
Author(s):  
P. Lampropoulou ◽  
C. Katagas
Keyword(s):  
High Purity ◽  
Raw Materials ◽  
World Market ◽  
Cement Industry ◽  
Refractory Materials ◽  
Secondary Phases ◽  
High Position ◽  
Spinel Refractory ◽  
Magnesia Spinel ◽  
Group B

In order for the Greek magnesia industry to retain a high position in the world market, the basic refractories derived from Greek magnesite must remain at the forefront of the international developments. A mineralogical study of magnesia materials produced from Evian magnesite has been carried out with the aim a) to provide detailed characterization of products and microstructures derived from the firing processes of magnesia raw materials and b) to contribute to the development of new magnesia-spinel refractory materials from natural Greek magnesite. The magnesite of N. Evia, Greece, is micro- crystalline and has been used for the production of basic refractories because of the very low amounts of impurities such as CaO, S1O2, FeO(tot), B2O3 it contains . Magnesia materials studied here are: 1) Raw materials. The dead- burned magnesia grains examined are divided into two groups according to the mode of beneficiation of the raw magnesite: a) Dead burned magnesias produced from natural microcrystalline magnesite (Group A). b) Dead burned magnesias of high purity produced from natural microcrystalline magnesite (Group B). The chemical composition of these materials lies essentially in the MgO-CaO-SiC>2 system, since they contain only trace amounts of Fe2Û3 and AI2O3. Their microstructures vary widely in terms of proportions of direct MgO-MgO bonding, amounts and types of phases of the siliceous bonding and size of the periclase crystals. Dead burned magnesias of high purity are better sintered and contain lower amounts of secondary phases compared to magnesias of lower purity. 2) Commercial magnesia bricks derived from dead burned magnesia of high purity and magnesia chromite bricks derived from raw materials of dead burned magnesia of high purity and chromite from Africa. 3) New spinel-based composition and new magnesia-spinel refractory materials which have been synthesized for the needs of this study. The newly synthesized spinel-based composition (70wt% Al2O3-30wt% MgO) shows an increase in the bulk density as well as in the amount of spinel formed compared to available commercial qualities (50%wt AI2O3). 4) Using this new spinel-based composition and dead burned magnesia of high purity, two new magnesia-spinel refractory materials containing 10 and 20wt% AI2O3 were produced, with the aim to obtain more friendly to the environment magnesia refractories to substitute for the magnesia chromite bricks. The compositions of the magnesia spinel refractories thus produced were expected to show endurance in thermal shocks as well as in the corrosion from slags and friction, in order to have a wide application in steel, cement industry etc .

ADAPTATION AND DEVELOPMENT OF MILK PRODUCERS IN THE NEW ECONOMIC CONDITIONS

2020 ◽  
Author(s):  
В.Н. СУРОВЦЕВ ◽  
Е.Н. ПАЮРОВА
Keyword(s):  
Dairy Products ◽  
Raw Materials ◽  
Raw Milk ◽  
World Market ◽  
Food Prices ◽  
Economic Conditions ◽  
State Support ◽  
Demand Reduction ◽  
The World ◽  
Dairy Cattle Breeding

Проанализированы проблемы на рынке молока и молочных продуктов России в условиях глобального экономического кризиса: перепроизводство молока в основных странах-экспортерах, снижение закупочных цен на сырое молоко, снижение цен на биржевые товары в мире и России в 2020 году, тренд на уменьшение спроса на молочные продукты на мировом рынке в среднесрочном периоде, снижение общего спроса на молочные продукты на внутрироссийском рынке при падении реальных доходов населения, изменение структуры потребления. Проведена оценка новых возможностей и угроз для развития отрасли: со стороны потребителей — рост цен на продовольствие, снижение доходов; с позиции производителей молока — снижение закупочных цен, рост требований к сырью для производства продукции с увеличенными сроками годности, дефицит рабочей силы, вероятное сокращение господдержки в результате снижения цен на углеводороды, попытки регулирования цен; со стороны перерабатывающих предприятий — сокращение спроса, снижение цен на готовую продукцию вслед за мировыми ценами. Обоснованы приоритеты инвестирования в молочном скотоводстве и основные формы совершенствования государственной поддержки отрасли, обеспечивающие эффективную адаптацию производителей молока к новым экономическим условиям, повышение устойчивости отрасли при усилении макроэкономических рисков. The article analyzes the problems in the Russian milk and dairy products market in the context of the global economic crisis: overproduction of milk in the main exporting countries, lower purchase prices for raw milk, lower prices for commodities in the world and in Russia in 2020, trend to reduce demand for dairy products on the world market in medium term, a decrease in total demand for dairy products in the Russian market with a decrease in the purchasing power of the population, a change in the structure of consumption. An assessment of new opportunities and threats to the development of the industry was carried out: on the part of consumers — rising food prices, lower incomes; from the perspective of dairy producers — reduction in purchase prices, increased requirements for raw materials for the production of products with extended periods, labor shortages, the likely reduction in state support as a result of lower prices for hydrocarbons, attempts to regulate prices; on the part of processing enterprises — reduction of demand, reduction of prices for finished goods following world prices. The investment priorities in dairy cattle breeding and the main forms of improving state support for the industry, ensuring the effective adaptation of milk producers to new economic conditions, increasing the sustainability of the industry with increasing macroeconomic risks, are substantiated.

Ukraine’s foreign trade in meat and meat products: trends and geographical aspects

2020 ◽  
pp. 48-52
Author(s):  
Olena Lyakhovska
Keyword(s):  
Small Businesses ◽  
Structural Changes ◽  
Raw Materials ◽  
Meat Products ◽  
World Market ◽  
Poultry Meat ◽  
Positive Development ◽  
Meat Production ◽  
Meat Industry ◽  
Geographical Structure

Current trends in meat and meat products exports are considered. The dynamics and structural changes in meat exports by types and degree of processing (beef and veal, pork, poultry, finished meat products) are analyzed. The paper proves that in recent years, only meat and edible poultry by-products have taken a competitive position in the world market. Accordingly, the dynamics of exports of this type of meat is positive, and the share of these products in the structure of exported meat is the largest (86.09%). Possible threats to the growth of import dependence on certain types of meat products, in particular, chilled and frozen beef and veal, pork, are indicated. The rating of the largest countries-importers of meat and meat products (by types) from Ukraine is built, their share in the structure of meat exports is determined. Changes in the geographical structure of exports have been studied, which indicate a low level of diversification of the geography of exports of certain types of meat (pork, beef). At the same time, a positive development of the geographical structure of poultry meat exports (exported to more than 100 countries) was revealed. Problems of the export potential development in the meat industry of Ukraine are revealed. In particular, the problems of livestock development (outdated technologies and production techniques that reduce the efficiency and productivity; inefficiency of the organization of purchase and processing of meat, which leads to reduced breeding in small businesses and households; inefficiency of state incentives, etc.) and industrial meat production (lack of raw materials, obsolescence of fixed assets and production technologies, poorly developed logistics, etc.). The solution of these problems requires: a systematic approach, which will encourage the cooperation of agricultural and industrial production, cooperation with importers of meat products and protection of domestic producers in the domestic and international markets, creating a favorable investment and information environment that will promote the meat industry development.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

PLZT:Nd3+ Ceramics for Photonic Applications

2012 ◽  
Vol 82 ◽  
pp. 32-37 ◽  
Author(s):  
Malgorzata Plonska ◽  
Wojciech A. Pisarski ◽  
Beata Wodecka-Dus ◽  
Lukasz Cienki
Keyword(s):  
Optical Properties ◽  
High Purity ◽  
Raw Materials ◽  
Ceramic Materials ◽  
Ceramic Powders ◽  
Pressing Method ◽  
All Ceramic ◽  
Neodymium Concentration ◽  
Sintering Conditions ◽  
Dielectric And Optical Properties

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.

Research on Purification Technology of Ultra-Large Flake Graphite Based on Alkali-Acid Method

2021 ◽  
Vol 1036 ◽  
pp. 104-113
Author(s):  
Hong Fei Guo ◽  
Bao Chao ◽  
Zeng Qi Zhao ◽  
Ding Nan
Keyword(s):  
Carbon Content ◽  
High Purity ◽  
Raw Materials ◽  
Acid Leaching ◽  
Flake Graphite ◽  
Fixed Carbon ◽  
Fusion Temperature ◽  
Acid Method ◽  
Fixed Carbon Content ◽  
Flake Structure

Graphite is a strategically scarce resource, and the preparation of high-purity graphite is the prerequisite and basis for the application of graphite. In order to determine the optimal purification technology parameters of an ultra-large flake graphite mine pneumatic separation ore with a fixed carbon content of 77.69%, a particle size of mainly 10 to 40 mesh, and main impurities of calcium carbonate, iron oxide and silica , two additional experiments of acid method and alkali method were added on the basis of alkali-acid method, to investigate the purification effect of different technological processes and acid leaching times on graphite raw materials, as well as to analyze the retention extent of different methods and alkali fusion temperature on graphite ultra-large flake structure. The results show that all three methods can increase the fixed carbon content of graphite to above 99%. However, compared with the acid method and the alkali method, the alkali-acid method can obtain high-purity graphite while also better protecting the graphite's ultra-large flake structure. The optimal fusion temperature is 400 °C, the optimal acid leaching time is 30% sulfuric acid thrice and 5% hydrofluoric acid once. After purification, the fixed carbon content of the product exceeds 99.97%.

Assessment of the positions of the exporting countries of agri-food products on the world market according to their role in global value chains

2021 ◽  
pp. 8-14
Author(s):  
Elena Yu. Frolova ◽  
Keyword(s):  
Raw Materials ◽  
Action Plan ◽  
Value Added ◽  
Global Value Chains ◽  
World Market ◽  
Point Of View ◽  
Value Chains ◽  
Agricultural Exports ◽  
Export Policy ◽  
The World

The place in the rankings of agricultural exporting countries in world trade is estimated in terms of the volume of imports and exports of raw materials and food. However, to assess the efficiency of agricultural exports, it is important to analyze the value added of exported goods produced in the country. The position of the exporting country in global value chains is derived from the type of agricultural production, which in turn depends on the level of development of the national economy, the availability and breadth of use of modern high technologies. The article examines the concept of the development of world agriculture from the point of view of the formation of global value chains, set out in the report of the UN World Food Organization [1] in comparison with the political decisions of such countries as India and the People’s Republic of China in the development of agricultural and food exports. The paper analyzes the risks associated with the consolidation of developing countries as suppliers of agricultural raw materials, as well as the conditions and action plan that allow the country-exporter of agricultural raw materials to move to higher levels in the global value chains on the world market. This experience should be considered to make comprehensive and effective decisions on the formation of the export policy of agricultural products and food of the Russian Federation, considering the food security of the country.

scholarly journals World corn market: analysis, trends and prospects of its deep processing

2020 ◽  
pp. 96-111
Author(s):  
Natalia Tanklevska ◽  
Viktoriia Petrenko ◽  
Alla Karnaushenko ◽  
Kateryna Melnykova
Keyword(s):  
Raw Materials ◽  
Investment Project ◽  
World Market ◽  
Raw Material ◽  
Deep Processing ◽  
Industrial Enterprises ◽  
Grain Processing ◽  
The World ◽  
The Usa ◽  
Corn Processing

Purpose. The purpose of the article is to determine the prospects of deep processing of corn in Ukraine, taking into account the restraining factors of development, on the basis of the analysis of the state and tendencies of functioning of the world market of corn. Methodology / approach. During the research, general scientific and special research methods were used, in particular: analysis and synthesis, scientific abstraction – in determining the purpose and formulating conclusions; comparative, calculation, statistical and graphical ones – in the assessment, analysis, comparison and establishment of patterns of the current state and trends in the production of corn and its deep processing; program-target one – to substantiate the factors of intensification of deep processing of corn in Ukraine. Results. The analysis was carried out and tendencies of world corn production were determined. The shares of countries-producers and countries-consumers of corn were calculated; their dynamics of changes were analyzed. Analysis of the dynamics of prices for corn grain on the Chicago Mercantile Exchange indicates that the price of raw materials is gradually declining, so agricultural enterprises that sell corn as a raw material, lose income from its production. The structure of corn use in different directions in the world was analyzed, and the structure of its use in the USA was considered in more detail. Factors of activation of deep processing of corn were identified. In Ukraine, deep grain processing as an industry is just beginning to develop, so it is worth processing corn, based on the experience of leading countries, such as the USA and China. Estimated costs for the construction of a modern plant for deep processing of corn and income from the implementation of this investment project were calculated. Originality/scientific novelty. The scientific novelty of the study is a comprehensive analysis of the world corn market; economic substantiation of expediency of corn processing in Ukraine; improving the system of factors to intensify the development of deep processing of corn in Ukraine. Practical value / implications. The practical value of the results of the study is that they will contribute to the formation of the concept of intensifying the development of deep processing of corn in Ukraine. The main results can be used by agro-industrial enterprises during the development of deep corn processing projects.

scholarly journals REGIONAL TECHNOLOGICAL LEARNING IN TURKISH CEMENT INDUSTRY

2020 ◽  
Vol 8 (4) ◽  
pp. 204-216
Author(s):  
Gurkan Calmasur ◽  
◽  
Meryem Emre Aysin ◽  
Keyword(s):  
Learning Curve ◽  
Linear Models ◽  
Raw Materials ◽  
Analysis Data ◽  
Vital Role ◽  
Learning Curves ◽  
Cement Industry ◽  
Company Performance ◽  
Technological Learning ◽  
The Impact

The learning curve reflects the reduction in average costs as the company's cumulative production increases. These curves are utilized when measuring company performance, managing production processes, and planning. In terms of cost reduction and profitability, the impact of learning is particularly important. The learning curves have been traditionally used in industries. In this study, the learning curves concerning the cement industry are examined. The cement sector inherits a high export potential in Turkey. Additionally, it is the industry branch that supplies the raw materials needed by countries' construction industries. On the other hand, the construction sector is a leading sector that mobilizes other markets. This sector is a major contributor to production, investment, and employment and plays a vital role in the development of the country. This paper aims to make a detailed analysis of the learning curves regarding the Turkish cement industry at the regional level covering the 2000-2018 period. In order to realize this aim, the linear and cubic learning models have been applied and the technological learning values for regions from 2000 to 2018 have been calculated. For the analysis, data of 68 factories operating in the Turkish cement industry obtained from Turkey Cement Manufacturers' Association have been used. The estimated results suggest that cubic models explain technological learning better than the linear models. The results indicated that learning levels differed across regions and times. While the highest learning level was observed in 2004, the highest level of forgetting was recorded in 2018. Finally, we can state that the learning curve of the Turkish cement industry between 2000 and 2018 is convex.

scholarly journals A Life-Cycle Approach to Integrate Environmental and Mechanical Properties of Blended Cements Containing Seashell Powder

2021 ◽  
Vol 13 (23) ◽  
pp. 13120
Author(s):  
Fatemeh Soltanzadeh ◽  
Ali E. Behbahani ◽  
Eduardo N. B. Pereira ◽  
Carlos A. Teixeira
Keyword(s):  
Life Cycle ◽  
Carbon Dioxide Emissions ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Blended Cement ◽  
Cement Industry ◽  
Optimal Dosage ◽  
Life Cycle Approach ◽  
Natural Pozzolan ◽  
Cement Production

The adverse consequences of producing ordinary Portland cement (OPC) on the environment have introduced cement production as the fourth largest source of anthropogenic carbon emissions after petroleum, coal, and natural gas. Managing and reducing the environmental concerns regarding the impacts of cement production on the environment, namely the depletion of non-renewable fuel resources, consumption of natural raw materials, and releasing huge amounts of CO2 into the atmosphere should be, therefore, one of the key priorities of the cement industry. Application of locally available minerals and wastes that can be blended with OPC as a substitute could considerably reduce the environmental impact. The present study evaluates the potentiality of waste seashell to be used as an additive in the production of blended cement through a modified life cycle approach integrating environmental and mechanical performances. In this regard, 34 cements consisting of different blends of OPC, seashell powder (within the range of 4–30% by OPC mass), and natural pozzolan (up to 30% by OPC mass) were tested to identify the optimal dosage of OPC substitution. Environmental impacts of the cements were assessed through life-cycle analysis. The possibility of mitigating the carbon dioxide emissions in the production of cements, with similar mechanical performance compared to that of OPC, was evaluated by considering both the mechanical and environmental results. The outcome of this study introduced more environment-friendly and sustainable options for future cements.

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