The Usage of Industrialwaste Materials for the Productionof Special Cements and Binders

1994 ◽  
Vol 370 ◽  
Author(s):  
Herbert PÖllmann ◽  
JÜrgen Neubauer ◽  
Hubert Motzet
Keyword(s):  
Fluidized Bed ◽  
Rotary Kiln ◽  
Laboratory Experiments ◽  
Fabrication Process ◽  
Industrial Wastes ◽  
Hydration Process ◽  
Power Station ◽  
Cement Production ◽  
Rapid Hardening ◽  
Calcium Sulfoaluminate

AbstractBy mixing various industrial wastes, as garbage combustion ashes, bottom ashes, fluidized bed ashes, lignite power station ashes, fume purification sulfates and sulfites and lime it is possible to produce cements and binders on the basis of alinite, calcium sulfoaluminate and belite depending on the chemical variety of used wastes.The fabrication process for these cements was studied by laboratory experiments and the different phases and properties were studied in detail. Alinite cement was already produced on a larger scale in a rotary kiln of 10m length. These cements can be used for application purposes in mining mortars, expansive cements, rapid hardening binders and in landfill technologies. The hydration process and workability can be controlled by using various additives. hus industrial wastes can be a secondary resource for special cement production.

Exergoeconomic Analysis in a Cement Production Plant

2020 ◽  
Author(s):  
J. Fajardo ◽  
A. Mendoza ◽  
D. Barreto ◽  
H. Valle
Keyword(s):  
Rotary Kiln ◽  
Relative Difference ◽  
Accurate Information ◽  
Production Plant ◽  
Production Plan ◽  
Exergy Destruction ◽  
Cement Production ◽  
Total Cost ◽  
Significant Difference ◽  
Exergoeconomic Analysis

Abstract A dry-type Cement Production Plan of 151 Tons per hour was taken as a case of study to implement an exergoeconomic analysis. In this paper, the exergy destruction and the investment costs of the system’s units were calculated to obtain accurate information about the performance of the process, from the exergoeconomic factor and the relative difference cost. Conventional exergoeconomic analysis showed that the total cost of exergy destruction is 4206537 USD/h. The Calciner and the Rotary Kiln cause 62% of the total cost of the exergy destruction. The lowest values of the exergoeconomic factor were calculated for Calciner (0.01%), Clinker Cooler (0.01%), Rotary Kiln (0.02%), and Raw Mill (0.04%). The significant difference in relative cost was calculated for Calciner (42%) and Rotary Kiln (54.21%). The above implies that this equipment should be considered for an investment that allows the decrease of the exergy destruction cost and the increase of the exergetic efficiency.

Retrofitting 25T/h Pulverized Coal-Fired Boiler Into 35T/h Circulating Fluidized Bed Boiler for Burning Mixture of Coal and Bagasse

2005 ◽  
Author(s):  
Han-Ping Chen ◽  
Xian-Hua Wang ◽  
Shi-Hong Zhang ◽  
De-Chang Liu ◽  
Yu-Hua Lai ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Efficiency ◽  
Economic Benefits ◽  
Pulverized Coal ◽  
Industrial Wastes ◽  
Pollutant Emission ◽  
Fluidized Bed Combustion ◽  
Circulating Fluidized Bed Boiler ◽  
Combustion Technology

In China, there are a large number of pulverized coal-fired industrial boilers, whose steam capacities are usually relatively small. These boilers can burn only high-grade coal and have low combustion efficiency. Furthermore, the combustion emissions, such as SO2 and NOx, pollute the environment severely. Therefore it is very important and urgent to adopt economically efficient and environmentally friendly technologies to retrofit these boilers. At the same time, there are many industrial wastes, such as bagasse, wood waste, rubbish, petroleum coke and so on, need burning disposal in China. Fluidized bed combustion technology is a kind of clear combustion technology, which has many advantages, such as excellence fuel flexibility, high combustion efficiency, low pollutant emission and good turndown capability etc. So, adopting fluidized bed combustion technology, retrofitting pulverized coal-fired boiler into fluidized bed boiler can realize pure burning various wastes or co-firing with coal, which should have great economic benefits and social benefits. And the application prospect of the method is also extensive. The State Key Laboratory of Coal Combustion has successfully retrofitted a 25t/h pulverized coal-fired boiler into circulating fluidized bed boiler with in-bed tubes and downward exhaust cyclone. The retrofitted boiler can burn mixture of coal and bagasse and the steam capacity reaches 35t/h. This paper presents the retrofitting measures and the operation status of the boiler after retrofitting.

PCR-DGGE analysis of denitrifying bacteria in a metallurgic wastewater treatment process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 333-336 ◽  
Author(s):  
N. Noda ◽  
S. Yoshie ◽  
T. Miyano ◽  
S. Tsuneda ◽  
A. Hirata ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Precious Metals ◽  
Packed Bed ◽  
Population Diversity ◽  
Operating Conditions ◽  
Industrial Wastes ◽  
Wastewater Treatment Process ◽  
Dgge Analysis ◽  
Gradient Gel Electrophoresis

The wastewater generated from the processes of recovering precious metals from industrial wastes contains high concentrations of acids such as nitric acid and of salts. Biological nitrogen removal from this wastewater was attempted by using a circulating bioreactor system equipped with an anoxic packed bed or an anoxic fluidized bed and an aerobic three-phase fluidized bed. The system was found to effectively remove nitrogen from the diluted wastewater (T-N; 1,000–4,000 mg litre−1). The microbial population structure of activated sludge in an anoxic reactor was analyzed by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA (rDNA) fragments. DGGE analysis under different operating conditions demonstrated the presence of some distinguishable bands in the separation pattern, which were most likely derived from many different species constituting the microbial communities. Furthermore, the population diversity varied in accordance with the nitrate-loading rate, water temperature and reactor condition. Some major DGGE bands were excised, reamplified and directly sequenced. It was revealed that the dominant population in the anoxic reactor were affiliated with the β subclass of the class Proteobacteria.

scholarly journals Green Process for Industrial Waste Transformation into Super-Oxidizing Materials Named Alkali Metal Ferrates (VI)

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1977 ◽  
Author(s):  
Ndue Kanari ◽  
Etleva Ostrosi ◽  
Cécile Diliberto ◽  
Inna Filippova ◽  
Seit Shallari ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Industrial Effluents ◽  
Transformation Process ◽  
Industrial Wastes ◽  
Iron Sulfate ◽  
Synthesis Process ◽  
Second Step ◽  
Sulfate Heptahydrate ◽  
Complete Control ◽  
Alkali Hydroxides

The investigation presented here features the design of a cleaner and greener chemical process for the conversion of industrial wastes into super-oxidizing materials. The waste of interest is the iron sulfate heptahydrate (FeSO4·7H2O) mainly generated through the sulfate route used for titanium dioxide industrial production. The products of this transformation process are alkali ferrates (A2FeO4, A = Na, K) containing iron in its hexavalent state and considered as powerful oxidants characterized by properties useful for cleaning waters, wastewaters, and industrial effluents. The proposed process includes two steps: (i) The first step consisting of the pre-mixing of two solids (AOH with FeSO4·xH2O) in a rotary reactor allowing the coating of iron sulfate in the alkali hydroxides through solid–solid reactions; and (ii) the second step involves the synthesis of alkali ferrates in a fluidized bed by oxidation of the single solid obtained in the first step in diluted chlorine. The chemical synthesis of alkali ferrates can be carried out within a timeframe of a few minutes. The usage of a fluidized bed enhanced the energy and mass transfer allowing a quasi-complete control of the ferrate synthesis process. The alkali ferrate synthesis process described here possesses many characteristics aligned with the principles of the “green chemistry”.

Analysis and Depiction of the Dynamical Characteristic of Burning Zone Temperature in Rotary Kiln of Cement Material Production

2012 ◽  
Vol 568 ◽  
pp. 208-211
Author(s):  
Wei Qing Ge ◽  
Bo Xiang ◽  
Ping Zhou
Keyword(s):  
Rotary Kiln ◽  
Building Materials ◽  
Complex Dynamics ◽  
Dynamical Characteristic ◽  
Cement Production ◽  
Dynamical Characteristics ◽  
Burning Zone ◽  
Novel Approach ◽  
Zone Temperature

The cement is one of the most important building materials, and the rotary kiln is a key equipment or process in the cement production industry. During the operating of the cement rotary kiln, the burning zone temperature (BZT) is an important production index and has a significant role on the quality of the clinker. However, the BZT has complex dynamic characteristic and is difficult to be described online using the conventional approaches. Although the BZT can be detected by using the expensive infrared pyrometer which located at the kiln head hood, it generally loses veracity due to the complex dynamics of the cement rotary kiln. In this paper, a novel approach is proposed to analyze and depict the dynamical characteristics of the BZT. Industrial tests have been performed to demonstrate the effectiveness and validity of the proposed method.

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