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Stefan G.,Instytut Mechanizacji Budownictwa i Gornictwa Skalnego
Gospodarka Surowcami Mineralnymi / Mineral Resources Management | Year: 2012

In the construction industry carbonate aggregates are commonly used in processes such as concrete production. Aggregates which contain (in their mineral composition) dolomite and an admixture of clay minerals and amorphous silica,can react with alkalis. These reactions can lead to a destructive expansion in concrete. This article explains the mechanisms and the essence of this phenomenon. What is more, some effective and fast methods of the estimation and evaluation of Polish aggregates consisting of carbonate rocks suggests effective methods to determine the usefulness of Polish carbonate aggregates in concrete production are discussed in the paper. Underneath the quality criteria to determine the reactivity of the aggregates will be given. It has been agreed that alkaline reaction and expansion are two separate phenomena related to each other genetically. The aggregates in which reactions caused by clay-siliceous admixtures occur are subjected to expansion. Mineral composition of expansive aggregates as well as their texture indicate that epigenetic dolomites with a distinctive texture are the most reactive. Source

Kukielska D.,Instytut Mechanizacji Budownictwa i Gornictwa Skalnego
Prace Naukowe Instytutu Gornictwa Politechniki Wroclawskiej | Year: 2012

The article presents the possibility of changes in the scope and frequency of testing. Reference was made to the provisions of the standards for testing of possible adjustments. The results of studies showing the records specified by standards. Source

Research in mineral resources management clearly indicate that more substances known as waste become mineral resources in new technologies. The common meaning of the word "waste" is replaced with the term "potential mineral resource" and most recently as "secondary resource". This reflects both usage properties and potential benefits. Basing on statistical data (the end of 2011) the amount of waste produced by the economic sector in Poland is nearly 123,5 mil Mg. In this, hard coal mining waste constitute about 28 mil Mg, meaning nearly 23%. Additionally, it is estimated that nearly 480 mil Mg of such waste is deposited in the environment. The result of the data analysis is that around 80% of waste produced during exploitation and processing of minerals is - in order to avoid fees for dumping - used in economy. Only 30% of this is industrially used and almost 70% is applied in ground levelling, engineering works or in so called "ground constructions". This way the abundance of potential mineral is irretrievably lost. The basic legal act for waste management issues is the Act from 10 July 2008 on extractive waste (Dz. U. Nr 138, poz. 865) adapting to the existing Polish law Directive 2006/21/EC. The aim of this Act is to prevent production of waste in extractive industry, diminishing their negative influence on the environment and people's health. The major aim of the project "Foresight in priority and innovative technologies of hard coal mining waste management" is identification of leading technologies in mining waste management of primary meaning, as their development in next 20 years in Poland will be a priority as well as creating scenario of their development through applying systematized research methodology. The project is conducted by the consortium including Institute of Mechanised Construction and Rock Mining, Silesian Technical University in Gliwice and AGH University of Science and Technology in Cracow. The article presents current situation of hard coal mining waste management in Poland, including criteria of their economic usage. It also presents the diagnosis of current state of development in economic management of hard coal waste technologies, defines evaluation criteria of innovativeness of currently applied technological solutions, provides SWOT analysis results on institutional and technological level, scenarios for the development of innovative technologies for utilisation of hard coal mining waste and future research and development work. Source

The paper presents result of investigation of physical, chemical and energetic properties of steam coal slurries deposited in twenty four impoundments. Performed investigation include determination of chemical composition, moisture content, volatile matter, sulfur and calorific value at various states. Additionally, properties of coal slurry of particle size below 0.1 mm are presented. The paper presents also results of energetic potential analysis of coal slurries deposited in impoundments. Results shown are for "as received" basis and for concentrates after beneficiation. Coal slurries were beneficiated using the following techniques: hydrocyclone classifier-separator, centrifugal separator, Reichert spiral separator LD4 and flotation. Assessment of energetic potential was made for concentrate whereas losses of energetic potential due to beneficiation were estimated. The most effective method was flotation where the loss of energetic potential was 15% and varied from 3 to 31% depending on the impoundment. Average value of obtained concentrate was 25 057 kJ/kg being the highest among all of the methods. The research was performed under the development project Nr N R09 0006 06/2009 titled: "Identification of energetic potential of coal slurries in the national fuel balance and technological development strategy of their usage". The project is implemented by the Institute of Mechanized Construction & Rock Mining in Warsaw in cooperation with the Department of Mineral Processing and Waste Utilization of the Silesian University of Technology. Source

Stankiewicz J.,Instytut Mechanizacji Budownictwa i Gornictwa Skalnego
Prace Naukowe Instytutu Gornictwa Politechniki Wroclawskiej | Year: 2013

A proposal of waste management generated at different stages of aggregates production was showed. Technology research was conducted on a laboratory scale. The results indicate the possibilities of a complete management of waste from rock mining providing an individual determination of parameters of production technology for hydraulically bound mixtures. Source

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