Cement Manufacturing Industry Research Articles

CO 2 emissions from Polish cement industry

The cement industry is one of the most significant sources of anthropogenic emissions of CO 2. It is connected with the specific character of the production processes, during which great quantities of CO 2 are produced. Basic actions to reduce CO 2 emissions recommended by the European Union's, Reference Document on Best Available Techniques in the Cement and Lime Manufacturing Industries, include: reduction of fuel consumption, selection of raw materials with low content of organic compounds and fuels with low coal contribution to heating value. All actions connected with the improvement of energy conversion efficiency of the cement production process cause CO 2 emissions reduction. The use of at most acceptable by the valid standards amounts of waste as raw materials and additives for cement production, also brings about the reduction of significant part of CO 2 emissions. These measures have been and continue to be pursued by the cement factories in Poland. This article describes the evolution of the cement industry in Poland over the period 1998–2008 and the resulting changes in CO 2 emissions and explores the drivers for these changes. The sources of CO 2 emissions in cement industry have been presented in this article as well as a discussion of potential ways to reduce Polish cement industry emissions even further.

Cleaner Production for Sustainable Industrial Development: Concept and Applications

In the 21st century, no business can successfully operate in an economic and social vacuum. Enterprises can achieve enduring success only by meeting the needs and the expectations of all their key constituents: customers, investors, employees, and the greater society. Sustainable development (SD) demands attaining the three-dimensional balance between economic growth and social and environmental responsibility; therefore, sustainability entails the continuous fulfillment of the varying needs and sometimes-conflicting objectives of the multiple stakeholders. Cleaner production (CP) is a proactive environmental strategy, a step beyond waste handling or management (based on the “cradle-to-cradle” approach). It deals with the source of the problem (i.e., pollution prevention, P2), rather than the effects and consequences (i.e., end-of-pipe treatment and/or corrective remediation). CP is also a practical approach of moving towards SD by allowing industries and service providers to produce more with less: fewer raw materials, less energy, less waste and emissions, and normally, less environmental impact and greater sustainability. CP, by definition, promises greater profits to industries by reducing costs (i.e., reduced material requirements, reduced disposal fees, and reduced environmental liabilities and cleanup costs) and by raising revenues through perhaps greater sales, exports, and better public relations (PR). CP has been applied to develop more environmentally benign (or even friendly) processes, products, services, and impacts. The implementation of CP involves specific methodologies for integrating environmental issues and sustainable development in a particular industry, employs applications of relevant analyses and syntheses, and above all challenges the traditional procedures for design, manufacturing applications, and services. This paper provides an overall view of CP as a concept, its principles, methods, and tools; its wide applications; and indeed its impediments. Several industrial examples of CP applications for conserving resources, minimizing wastes and emissions, reducing risks, and curtailing costs and generating profits are presented. Case studies from the chemical, textile, and cement manufacturing industries are illustrated. Through these examples it can be demonstrated that industry and the environment are not mutually exclusive but rather complementary in achieving SD.

CHEMICAL ANALYSIS OF SOME NIGERIAN GYPSUM AND LIMESTONE SAMPLES UTILIZED BY A LEADING CEMENT MANUFACTURING INDUSTRY

X-ray fluorescence analyzer (XRF) was employed in the analysis of some local and imported stocks of gypsum and limestone utilized by a leading cement manufacturing industry in Nigeria. In addition, the recycled dust standard reference samples were also analyzed along with the raw materials in question. The gypsum samples were found to have purity varying between 86.3% and 96.17% for both local and imported stocks. The limestone stock had purity of 42.2% to 95.39%, and these samples were obtained locally within and outside the factory location. Impurities detected at a measurable level included Na, K, Al, Si, Mg and S, and these were calculated as their respective oxides. The production economy of the industry was appraised with respect to total dependence on locally produced gypsum. Global Jnl Pure & Applied Sciences Vol.10(1) 2004: 87-90

Application of Uniform Design in the Formation of Cement Mixtures

As products and processes become more and more complex, there is an increasing need in the industry to perform experiments with a large number of factors and a large number of levels for each factor. For such experiments, application of traditional designs such as factorial designs or orthogonal arrays is impractical because of the large number of runs required. As an alternative, a type of design, called the uniform design, can be used to solve such problems. The uniform design has been intensively studied by theoreticians for several decades and has many successful examples of application in industry. In this article, we report a successful application of uniform design in product formation in the cement manufacturing industry. Specifically, we investigate the effects of additives on bleeding and compressive strength of a cement mixture. This example illustrates how an experiment of 16 runs was performed to study three factors with 16 levels, 8 levels, and 8 levels, respectively.

Cement Manufacture and the Environment Part II: Environmental Challenges and Opportunities

SummaryConstruction materials account for a significant proportion of nonfuel materials flows throughout the industrialized world. Hydraulic (chiefly portland) cement, the binding agent in concrete and most mortars, is an important construction material. Portland cement is made primarily from finely ground clinker, a manufactured intermediate product that is composed predominantly of hydraulically active calcium silicate minerals formed through high‐temperature burning of limestone and other materials in a kiln. This process typically requires approximately 3 to 6 million Btu (3.2 to 6.3 GJ) of energy and 1.7 tons of raw materials (chiefly limestone) per ton (t) of clinker produced and is accompanied by significant emissions of, in particular, carbon dioxide (CO2), but also nitrogen oxides, sulfur oxides, and particulates. The overall level of CO2 output, about 1 ton/ton clinker, is almost equally contributed by the calcination of limestone and the combustion of fuels and makes the cement industry one of the top two manufacturing industry sources of this greenhouse gas. The enormous demand for cement and the large energy and raw material requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels and provide the industry with significant opportunities to symbiotically utilize large quantities of by‐products of other industries.This article, the second in a two‐part series, summarizes some of the environmental challenges and opportunities facing the cement manufacturing industry. In the companion article, the chemistry, technology, raw materials, and energy requirements of cement manufacture were summarized. Because of the size and scope of the U.S. cement industry, the article relies primarily on data and practices from the United States.

Enhancing management's understanding of operational research models

The problem of the gap between management's understanding of a model and the model builder's insight is a large one. This problem continues to challenge the practice of operational research and plague contemporary modelling efforts. This paper offers an approach to enhancing a manager's understanding of the model with respect to an application. It sets out a procedure whereby (a) the reasons for the management's judgements are uncovered, and (b) the sources of disagreement with the recommendations obtained from the model are identified. The manager, learning from the model, may then change his or her judgements. Alternatively, the model builder may modify the model parameters or assumptions, leading to convergent understanding. The procedure is based on the framework of social judgement theory. An illustrative example is offered in the context of facility planning in the cement manufacturing industry.

Malignant Mesothelioma in Australia (1945–1995)

In Australia, more chrysotile than amphibole asbestos was mined until 1939. With the commencement of mining at Wittenoom, Western Australia in 1937, crocidolite dominated production, until final closure in 1966. New South Wales, the first State to mine asbestos, also produced the largest tonnages of chrysotile (until 1983) as well as smaller quantities of amphibole (until 1949). With the closing of the crocidolite mine at Wittenoom in 1966, Australian asbestos production and exports declined. Imports of chrysotile also started to decline. The main sources of raw asbestos imports were Canada (chrysotile) and South Africa (crocidolite and amosite). In addition to imports of asbestos fibre, Australia also imported many manufactured asbestos products, including asbestos cement articles, asbestos yarn, cord and fabric, asbestos joint and millboard, asbestos friction materials and gaskets. The main sources of supply were the United Kingdom, U.S.A., Federal Republic of Germany and Japan. In Australia over 60% of all production and 90% of all consumption of asbestos fibre was used by the asbestos cement manufacturing industry. From about 1940 to the late 1960s all three types of asbestos were used in this industry, crocidolite then being phased out. Much of this industry output remains in service today in the form of fibro houses and water and sewerage piping. By 1954 Australia was number four in the Western world in gross consumption of asbestos cement products, after U.S.A., U.K. and France, and clearly first on a per capita basis. From World War II to 1954, 70 000 asbestos cement houses were built in the state of New South Wales alone (52% of all houses built). In Australia as a whole, until the 1960s, 25% of all new housing was clad in asbestos cement. Exposures in the past were very high in some industries and jobs [e.g. 25 million particles per cubic foot (150 fibres ml) in asbestos pulverisors and disintegrators in the asbestos cement industry; up to 600 fibres ml in baggers at Wittenoom]. Australia still imports about 2000 tonnes a year of chrysotile fibre and about $A13.5m worth of asbestos products a year, over half as friction material but also fabricated yarn, fabric, jointing, gaskets, millboard and asbestos cement products. Handling of asbestos in place and removal operations are subject to a strict National Code of Practice. A series of regulations adopted in the late 1970s and early 1980s by the various states now impose exposure limits of 0.1 fibre mP 1 for crocidolite, amosite and mixtures and 0.1-1.0 fibre ml for chrysotile (TWA 8 h membrane filter method light microscopy, WHO fibres).

The regulation of hazardous air pollutants under the Clean Air Act Amendments of 1990: effects on the Portland cement industry

Title III of the 1990 Clean Air Act Amendments (CAAA) addresses the control of hazardous air pollutants (HAPs) from major sources of air pollution in the United States. In the CAAA, Congress defined 189 compounds as hazardous air pollutants in need of additional control by the Environmental Protection Agency (EPA). Congress directed EPA to identify the major source categories which emit HAP's and to prepare regulations that would reduce and control future HAP emissions. This paper outlines the activities undertaken by EPA to regulate HAP emissions from Portland cement plants and the program developed by the Portland cement manufacturing industry to cope with Title III.

U.S. ENVIRONMENTAL PROTECTION AGENCY REGULATION OF THERMAL DISCHARGES

Regulation of the thermal component of aqueous effluent discharges into U.S. waters from industrial point sources by the U.S. Environmental Protection Agency is authorized according to the provisions of the Water Pollution Control Act Amendments of 1972 (Public Law 92–500). Recent (1977) amendments to the Law have little effect on EPA’s thermal regulation strategy.Technology-based limitations on the temperature at which an effluent may be discharged have been established for certain industrial categories. Specific effluent limitations for the Beet Sugar Industry, Cement Manufacturing Industry, and Steam Electric Power Generation Industry are discussed. State Water Quality Standards also limit heated discharges in certain instances. The mechanism is outlined for administering, monitoring and enforcing compliance with these limitations through the U.S. National discharge permit system.Additionally, Section 316 of Public Law 92–500, defines circumstances whereby thermal discharges, and related activities, ar...

Computer control in the cement industry

The cement manufacturing industry in the United States is described, as are the processing problems which make the utilization of computer control attractive. Computers are being used to assist in the proportioning of raw materials, the operation of the rotary kiln, and in the raw material and product grinding operations. Process measurement and identification problems currently preclude complete automation, but significant economic benefits have been realized and further progress is under way.