scholarly journals MODERN TECHNOLOGIES OF MATERIALS FOR PROTECTION THE WORKING SURFACES OF HYDROCLONE AGAINST WEAR

2019 ◽  
Vol 4 (7) ◽  
pp. 135-139
Author(s):  
Ю.М. Фадин ◽  
Yuriy Fadin ◽  
П. Хахалев ◽  
Pavel Hahalev ◽  
Е. Трапезникова ◽  
...  
Keyword(s):  
Portland Cement ◽  
Cement Clinker ◽  
Cement Production ◽  
Wet Process ◽  
Working Surface ◽  
Hydraulic Binder ◽  
Calcium Silicates ◽  
Mineral Additives ◽  
Modern Technologies ◽  
Active Mineral Additives

The article considers the process of portland cement production by wet process. Portland cement is a hydraulic binder that is produced by cement clinker, gypsum and additives. Calcium silicates are commonly used as additives. Portland cement production consists of following processes: crushing of clinker and gypsum stone; preparation of mineral additives (crushing, drying); grinding of clinker with active mineral additives and gypsum; storage, packaging and shipping the cement to consumer. Since grinding is carried out in a closed cycle, it is necessary to select the classifying equipment. For this purpose, an analysis is made, which reveals that the hydrocyclone is the most multi-purpose and less expensive in operation of classifying equipment. The study of the hydrocyclone design demonstrates a significant drawback in the form of increased wear of the hydrocyclone working surfaces, which has an impact on durability and work efficiency. The degree of wear the hydrocyclone surfaces depends on the nature of the pulp impact and the mechanical characteristics of material of the hydrocyclone working surface. This article is devoted to the study of the most popular and frequently used wear-resistant materials to protect work surfaces from wear.

scholarly journals Volcanic Ash as a Sustainable Binder Material: An Extensive Review

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1302
Author(s):  
Andrés Játiva ◽  
Evelyn Ruales ◽  
Miren Etxeberria
Keyword(s):  
Chemical Composition ◽  
Portland Cement ◽  
Urban Areas ◽  
Volcanic Ash ◽  
Mechanical Performance ◽  
Cement Clinker ◽  
Alkali Activation ◽  
Cement Production ◽  
Sustainable Solutions ◽  
Alkali Activated

The construction industry is affected by the constant growth in the populations of urban areas. The demand for cement production has an increasing environmental impact, and there are urgent demands for alternative sustainable solutions. Volcanic ash (VA) is an abundant low-cost material that, because of its chemical composition and amorphous atomic structure, has been considered as a suitable material to replace Portland cement clinker for use as a binder in cement production. In the last decade, there has been interest in using alkali-activated VA material as an alternative material to replace ordinary Portland cement. In this way, a valuable product may be derived from a currently under-utilized material. Additionally, alkali-activated VA-based materials may be suitable for building applications because of their good densification behaviour, mechanical properties and low porosity. This article describes the most relevant findings from researchers around the world on the role of the chemical composition and mineral contents of VA on reactivity during the alkali-activation reaction; the effect of synthesis factors, which include the concentration of the alkaline activator, the solution-to-binder ratio and the curing conditions, on the properties of alkali-activated VA-based materials; and the mechanical performance and durability properties of these materials.

Gypsum-Free Portland Cement Pastes of Low Water-to-Cement Rat10

1994 ◽  
Vol 370 ◽  
Author(s):  
FrantiŠek ŠkvÁra
Keyword(s):  
Portland Cement ◽  
Surface Active Agent ◽  
Active Agent ◽  
Active Surface ◽  
Cement Clinker ◽  
Cement Pastes ◽  
The Czech Republic ◽  
Hydraulic Binder ◽  
Synergetic System ◽  
Main Component

AbstractGypsum-free portland cement is a low porosity hydraulic binder based on finely groundportland cement clinker with addition of synergetic system containing an anion-active surface active agent (usually a sulphonated polyelectrolyte) and an inorganic salt (usually sodium carbonate) for regulation of the hardening process. The properties of GF cement are different from ordinary portland cement; they display, for example, higher strength, better corrosion resistance and thermal stability. These positive differences arise from the different mineralogy and microstructure of the hydration products, for example the absence of portlandite crystals. The main component of the binder product in hardened GF cement pastes is C-S-H (mean C/S ratio 2.7, based on EDAX analysis) intergrown with very fine Ca(OH)2 and highly dispersed C-A-H phases (hexagonal and cubic). The absence of crystalline formations in the GF hardened pastes is responsible for highermechanical strength. In the Czech Republic, GF cement is produced in the cement works of CEVA Prachovice Inc. ( Holderbank group) and is used for special works in the building industry.

scholarly journals Geopolymer Cements and Their Properties: A Review

2015 ◽  
Vol 61 (2) ◽  
pp. 85-100 ◽  
Author(s):  
Vladimír Živica ◽  
Martin T. Palou ◽  
Martin Križma
Keyword(s):  
Carbon Dioxide ◽  
Portland Cement ◽  
Carbon Dioxide Emissions ◽  
Construction Material ◽  
Industrial Sector ◽  
Engineering Properties ◽  
Cement Clinker ◽  
Chemical Action ◽  
Cement Production ◽  
Geopolymer Cements

Abstract Concrete is the world's most versatile, durable and reliable construction material. Next to water, concrete is the second most used substance on earth and it requires large quantities of Portland cement. The industrial sector is the third largest source of man-made carbon dioxide emissions after the transportation sector as the major generator of carbon dioxide, which pollutes the atmosphere. Ordinary Portland cement (OPC) production produces the largest amount of carbon dioxide amongst all industrial processes. In addition to that a large amount of energy is also consumed for the cement production. The production of OPC not only consumes a huge amount of the natural resources i.e. limestone and fossil fuels but also produces almost 0.9 t of CO2 for 1t of cement clinker production. Thus, the world cement production generates 2.8 billion tons of manmade greenhouse gas annually. Hence, it is inevitable to find an alternative material to the existing most expensive, most resource and energy consuming Portland cement. Geopolymer cements are innovative binders which can be produced by the chemical action of aluminosilicate materials plenty available worldwide. They are rich in silica and alumina reacting with alkaline solution and producing aluminosilicate gel that acts as the binding material for the concrete. Geopolymers are synthesized by polycondensation reaction of geopolymeric precursor and alkali polysilicates. The paper presents data on the important engineering properties of geopolymer cements showing that these cements offer an alternative to, and potential replacement for, OPC. Geopolymer technology also has the potential to reduce global greenhouse emissions caused by OPC production. Due to the high level of mechanical properties of geopolymer cements and their environmentally beneficial technology they appear as a prospective construction material for the future.

scholarly journals Definition Of Puzzolanic Properties Active Mineral Additives In Portlandcement

2021 ◽  
Vol 03 (03) ◽  
pp. 7-12
Author(s):  
Gulsanam Ruzimurodovna Tursunova ◽  
◽  
Farrukh Bakhtiyarovich Atabaev ◽  
Keyword(s):  
Portland Cement ◽  
Cement Stone ◽  
Industry Waste ◽  
Natural Production ◽  
Production And Consumption ◽  
Mineral Additive ◽  
Definition Of ◽  
Mineral Additives ◽  
Mineralizing Additive ◽  
Active Mineral Additives

The article presents the results of testing the use of Angren dry remote active ash and slag in Portland cement as an active mineral additive. It was found that Portland cement with the addition of Angren dry remote active ash and slag renders karrazastoy, ekanomet clinker and it is proved that hydro removed ash and slag (2011 year) does not recommend as an active mineral additive. Therefore, dry remote active ash and slag is recommended for use as an active mineral additive in the production of cement, improving its construction and technical properties. The possibility of using Angren dry remote active ash and slag as an active mineral component for producing cements with low corrosion resistance is shown. Angren dry remote active ash and slag contributes to the formation of the structure of the cement stone, increases its density and strength against aggressive ions, causing increased resistance in aggressive environments. And save up to 30% of cement. It has been established that Portland cement with the addition of Angren dry remote active ash and slag has an intensifying effect on the formation of clinker minerals. Therefore, the Angren dry remote active ash and slag is recommended for use as a mineralizing additive in the production of cement. Use of chemical industry waste with replacement of expensive natural production and consumption waste. At the same time, an environmental problem is being addressed.

scholarly journals Estimation of Hydration Degree of Blended Cements with the Help of k-Values

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2420 ◽  
Author(s):  
Reiterman ◽  
Holčapek ◽  
Davidová ◽  
Jaskulski ◽  
Keppert
Keyword(s):  
Portland Cement ◽  
Ceramic Powder ◽  
Numerical Estimation ◽  
Time Intervals ◽  
Blended Cements ◽  
Degree Of Hydration ◽  
Mineral Additives ◽  
Furnace Slag ◽  
Active Mineral Additives

The growing utilization of various mineral additives in the building industry has caused concern worldwide to reduce the emissions of carbon dioxide from Portland cement (OPC) production. The present paper is focused on the determination of the degree of hydration of blended binding systems based on Portland cement. Blast furnace slag, fly ash, and ceramic powder are used in the study; they are applied by 12.5 wt.% up to 50% of OPC replacement. The evolution of the hydration process is monitored using thermogravimetry in selected time intervals to determine the degree of hydration; its ultimate value is obtained from numerical estimation using the Michaelis-Menten equation. However, due to the application of active mineral additives, the correction in terms of equivalent binder is conducted. Corrected values of the degree of hydration exhibit good fit with compressive strength.

Kinetic Consideration of Clinker Formation in Portland Cement Production Using Demolition Rubbles (Concrete,mortar and plaster) Part I : Burning Ability of Raw Mixes

2005 ◽  
Vol 5 (2) ◽  
pp. 169
Author(s):  
Sumardi P ◽  
I. B. Agra ◽  
I. M. Bendiyasa ◽  
Wahyudi B. S.
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Weight Ratio ◽  
Raw Material ◽  
Silica Sand ◽  
Cement Clinker ◽  
Cement Production ◽  
Operating Condition ◽  
Saturation Factor ◽  
Specific Operating Condition

Wahyudi B.S.Wahyudi B.S.In general, the main raw materials in Portland cement production are limestone, clay, and corrective materials such as iron sand and silica sand. These raw material come from natural deposits, which are very hard to find in some countries. In this research, Portland cement was made by utilizing the demolition rubble of office and housing buildings. The rubble consists of concrete wastes (mixtures of hydrated Portland cement minerals and some aggregates) and some building bricks as well as mortar/plaster of Portland cement. To meet the cement modulus, which is generally used in Portland cement industries, corrective materials such as limestone (source of CaO) and disposed building bricks are used. The term burning ability is used for Portland cement to measure the CaO free content in the cement clinker produced from specified raw material mixes at a specific operating 'condition of clinkering. The cement modulus used is Ume Saturation Factor (LSF) and Silica Modulus (SM). The minimum Cao free content was found by using LSF: 0.86, SM: 2.14, and clinkering temperature 14000C for 30 minutes. The cement modulus was made from concrete waste, limestone, and disposed red brick with a weight ratio of 1: 3.489: 0.677. Keywords: Burning ability,demolition rubble of buildings, Portland cement, and raw mixes.

scholarly journals The clays after heat treatment as the concrete active mineral additive

2018 ◽  
Vol 170 ◽  
pp. 03021
Author(s):  
Olga Bazhenova ◽  
Sofia Bazhenova ◽  
V. Nemirova ◽  
Dmitriy Bazhenov
Keyword(s):  
Heat Treatment ◽  
Portland Cement ◽  
Raw Material ◽  
Cement Stone ◽  
Material Resources ◽  
Mineral Additive ◽  
Granulated Slag ◽  
Technical Properties ◽  
Mineral Additives ◽  
Active Mineral Additives

Active mineral additives are one of the most common components of cement systems now. They are entered cements of increase in extent of hydration, the directed formation of structure of a cement stone from more stable hydrate phases of the lowered basicity, for the purpose of improvement of construction and technical properties of cements, by cutting of costs of fuel raw material resources for their production, giving to cements of some specific properties. In work the possibility of use as active mineral additives not only the granulated slags, but also local clays which industrially can give certain puzzolan properties are considered. It is proved that heat treatment of clay breeds significantly increases their puzzolan activity that does them suitable for use as active mineral additive instead of the domain granulated slag by production of the portland cement.

scholarly journals PORTLAND CEMENT WITH NATURAL MINERAL ADDITIVES

2019 ◽  
pp. 192-201 ◽  
Author(s):  
A. E. Mestnikov ◽  
A. I. Kudyakov ◽  
V. N. Rozhin
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Setting Time ◽  
Standard Test ◽  
Cement Clinker ◽  
The Arctic ◽  
Natural Mineral ◽  
The North ◽  
Portland Cement Clinker ◽  
Mineral Additives

One of the most effective developments of energy saving in the production of Portland cement used worldwide, is joint grinding of Portland cement clinker with injected mineral additives, such as pozzolanic rocks, ashes and slags.The aim of this work is to substantiate the possibility of the quality cement production using joint grinding of Portland cement clinker with natural mineral additives with a view to the of production location.River (quartz-feldspar) sands of the Lena basin and large-tonnage raw materials (zeolitecontaining rocks of the Khonguruu deposit) are considered as mineral additives to Portland cement. The study uses both standard test methods and the X-ray phase analysis for binders and concretes.The activity of the mineral additives to Portland cement is studied. The main properties of clinker, gypsum stone and mineral additives are studied to organize the production of quality Portland cement and products for the support of construction projects in the North-Eastern part of the Arctic and the North of Russia. The effect from additives and fineness of zeolitecontaining clinker and quartz-feldspar sand is studied relative to the thickness and setting time of the cement paste and cement mortar strength.It is shown that the types CEM II/A-P 32.5N and CEM II / A-P 42.5N Portland cement can be produced from imported Portland cement clinker and local mineral additives saving 5–15 % Portland cement clinker.

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