scholarly journals Substance Flow Analysis of Zinc in Two Preheater–Precalciner Cement Plants and the Associated Atmospheric Emissions

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 128
Author(s):  
Zhonggen Li ◽  
Yiming Huang ◽  
Xinyu Li ◽  
Guan Wang ◽  
Qingfeng Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Production Process ◽  
Flow Analysis ◽  
Distribution Patterns ◽  
Cement Industry ◽  
Environmental Stability ◽  
Anthropogenic Sources ◽  
Human Beings ◽  
Atmospheric Emission ◽  
Clinker Production

Atmospheric emission of heavy metals from different anthropogenic sources is a great concern to human beings due to their toxicities. In order to disclose the emission levels and the distribution patterns of zinc (Zn) in the modern cement industry with respect to its low boiling point (~900 °C) comparing to the high-temperature (1450 °C) clinker production process, solid samples representing the input and output flow of Zn during the entire production process in two preheater–precalciner cement plants (CPs) were collected and analyzed. For the first time, it was found that the behaviour of Zn inside different precalciner CPs was similar despite a huge difference in the Zn inputs to the CPs; namely, almost all the Zn input was output in clinker, which was then mixed with different additives and retarder to make cement products. The high-temperature clinkerisation process would incorporate Zn into the aluminosilicate of clinker. As a result, there was no enrichment of Zn during clinker production and the atmospheric emission factor was relatively low at 0.002%, or 1.28–9.39 mg Zn·t−1 clinker. Our result for the atmospheric Zn emissions from CPs was much lower than most previous reports, implying the CPs were not a crucial Zn emission source. However, the higher load of Zn in some raw/alternative materials—like nonferrous smelting slag with a Zn content of ~2%—could greatly increase the content of Zn in clinker and cement products. Therefore, further investigation on the environmental stability of Zn in such Zn-laden cement and concrete should be carried out.

scholarly journals Environmental Stability of High Temperature Molten Vitreous Residue of Hazardous Waste

2021 ◽  
Vol 647 ◽  
pp. 012082
Author(s):  
Xiu-Teng Wang ◽  
Guoliang Liu ◽  
Fei Fang ◽  
Ling Lin ◽  
Yang Zheng ◽  
...  
Keyword(s):  
High Temperature ◽  
Hazardous Waste ◽  
Environmental Stability

Recent Advances in Development and Processing of Titanium Aluminide Alloys

2000 ◽  
Vol 646 ◽  
Author(s):  
Fritz Appel ◽  
Helmut Clemens ◽  
Michael Oehring
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Environmental Stability ◽  
Physical Metallurgy ◽  
Specific Strength ◽  
Wide Range ◽  
Structural Applications ◽  
Strength And Stiffness ◽  
Nickel Base

ABSTRACTIntermetallic titanium aluminides are one of the few classes of emerging materials that have the potential to be used in demanding high-temperature structural applications whenever specific strength and stiffness are of major concern. However, in order to effectively replace the heavier nickel-base superalloys currently in use, titanium aluminides must combine a wide range of mechanical property capabilities. Advanced alloy designs are tailored for strength, toughness, creep resistance, and environmental stability. Some of these concerns are addressed in the present paper through specific comments on the physical metallurgy and technology of gamma TiAl-base alloys. Particular emphasis is placed on recent developments of TiAl alloys with enhanced high-temperature capability.

Effect of distribution patterns of refractory overlayers on cyclic high temperature CO2 capture using waste oyster shell

RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 97739-97748 ◽  
Author(s):  
Kun Qin ◽  
TsingHai Wang ◽  
Jin-Chiang Huang ◽  
Chih-Hung Huang ◽  
Yi-Kong Hsieh ◽  
...  
Keyword(s):  
High Temperature ◽  
Plasma Treatment ◽  
Co2 Capture ◽  
Oyster Shell ◽  
Distribution Patterns ◽  
Furnace Treatment

Plasma treatment induces a thin CaZrO3 overlayer while the furnace treatment allows CaZrO3 as a wedge between CaO particles.

Design multivariate statistical process control procedure in the case of Ethio cement

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Daniel Ashagrie Tegegne ◽  
Daniel Kitaw Azene ◽  
Eshetie Berhan Atanaw
Keyword(s):  
Neural Network ◽  
Production Process ◽  
Control Chart ◽  
Cement Industry ◽  
Time Interval ◽  
Control Procedure ◽  
Sufficient Information ◽  
Content Type ◽  
Multivariate Control Chart ◽  
Multivariate Control

PurposeThis study aims to design a multivariate control chart that improves the applicability of the traditional Hotelling T2 chart. This new type of multivariate control chart displays sufficient information about the states and relationships of the variables in the production process. It is used to make better quality control decisions during the production process.Design/methodology/approachMultivariate data are collected at an equal time interval and are represented by nodes of the graph. The edges connecting the nodes represent the sequence of operation. Each node is plotted on the control chart based on their Hotelling T2 statistical distance. The changing behavior of each pair of input and output nodes is studied by the neural network. A case study from the cement industry is conducted to validate the control chart.FindingsThe finding of this paper is that the points and lines in the classic Hotelling T2 chart are effectively substituted by nodes and edges of the graph respectively. Nodes and edges have dimension and color and represent several attributes. As a result, this control chart displays much more information than the traditional Hotelling T2 control chart. The pattern of the plot represents whether the process is normal or not. The effect of the sequence of operation is visible in the control chart. The frequency of the happening of nodes is recognized by the size of nodes. The decision to change the product feature is assisted by finding the shortest path between nodes. Moreover, consecutive nodes have different behaviors, and that behavior change is recognized by neural network.Originality/valueModifying the classical Hotelling T2 control chart by integrating with the concept of graph theory and neural network is new of its kind.

A Pre-Feasibility Study of Limestone Quarry Development for Cement Industry in Cambodia

2014 ◽  
Vol 931-932 ◽  
pp. 1696-1700
Author(s):  
Socheat Kem ◽  
Sunthorn Pumjan
Keyword(s):  
Feasibility Study ◽  
Early Stage ◽  
Flow Analysis ◽  
Cement Industry ◽  
Mine Planning ◽  
Rate Of Return ◽  
Internal Rate Of Return ◽  
Local Conditions ◽  
Planning And Scheduling ◽  
Internal Rate

s: Cambodia is a developing country, and mining sector is just started within the last 10 years. Many mining companies have started to explore and carry out the feasibility study amid the scarcity of geological data and technical code of practices. Therefore, the quarry sector is also considered at the early stage in Cambodia, and it is required a standard quarry planning practice. This paper will present the main concepts of (1) quarry operation, development, and design by using the commercial program Minesight to accommodate the mine planning and scheduling. as the result, 25 million ton of limestone was calculated to be a reserve with production of 1 million ton per year; (2) financial model, consisted of cash flow analysis, net present values (NPV), and the Internal Rate of Return (IRR) are the main point for economics consideration. In this point, 47% of internal rate of return was calculated with the net present values of 21.5 million US Dollar and (3) the environmental impact which involves dust, noise, vibration impacts and mine rehabilitation, will be addressed base on the specific local conditions.

scholarly journals Atmospheric emission inventory of cadmium from anthropogenic sources

2013 ◽  
Vol 11 (3) ◽  
pp. 605-616 ◽  
Author(s):  
K. Cheng ◽  
H. Z. Tian ◽  
D. Zhao ◽  
L. Lu ◽  
Y. Wang ◽  
...  
Keyword(s):  
Emission Inventory ◽  
Anthropogenic Sources ◽  
Atmospheric Emission

RAP Percentage and Warm Mix Additive Influence on Regenerated Asphalt Mixture Performance

2012 ◽  
Vol 251 ◽  
pp. 436-441 ◽  
Author(s):  
Wei Liu
Keyword(s):  
Adverse Effect ◽  
High Temperature ◽  
Low Temperature ◽  
Adverse Effects ◽  
Production Process ◽  
Asphalt Mixture ◽  
Economical Efficiency ◽  
Temperature Performance ◽  
Low Temperature Performance ◽  
Additive Influence

The warm mix regeneration technology has prominent economical efficiency that can not only reduce the secondary aging of new asphalt and old asphalt in RAP materials during the production process, but also improve the use proportion of RAP materials. As for the increase of RAP dosage and the warm mix additive added to influence the plant regenerated asphalt mixture performance, this paper adopts two kinds of warm mix additive for the test and analysis of the warm mix regenerated asphalt mixture performance with 20% and 60% RAP. The results indicate that magnify the proportion of RAP percentage makes contribution to further improve high-temperature performance of the regenerated mixture, but it has adverse effects on water resistant damage performance and low-temperature performance. At the same time, adopting the warm mix additive can significantly reduce the adverse effect, so warm mix regenerated technology has better feasibility.

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