scholarly journals Sintering of sepiolite-rich by-products for the manufacture of lightweight aggregates: technological properties, thermal behavior and mineralogical changes

2021 ◽  
Vol 71 (341) ◽  
pp. e241
Author(s):  
J. M. Moreno-Maroto ◽  
B. González-Corrochano ◽  
J. Alonso-Azcárate ◽  
C. Martínez-García

A sepiolite mining by-product (SEP) has been studied as major component for lightweight aggregate (LWA) manufacture. Pellet bursting during firing was avoided by the addition of 2.5 wt% of thermoplastic waste (P) and 2.5 wt% P + 2.5 wt% carbon fiber residue (FC) in powder form. The mixtures were pelletized and then sintered at 1225º˚C for 4 minutes in a rotary kiln. Highly porous white LWAs with good mechanical strength were produced. A mineralogical study revealed the formation of amorphous phase ( > 50%) and minor proportions of enstatite, protoenstatite and diopside. Quartz was the only inherited mineral, appearing in the form of isolated phenocrysts within a general porphyritic texture. The result of this study suggests the promising use of sepiolite (whether or not in residue form) for the manufacture of high quality LWAs.

2016 ◽  
Vol 126 ◽  
pp. 56-73 ◽  
Author(s):  
Muhammad Aslam ◽  
Payam Shafigh ◽  
Mohd Zamin Jumaat

2018 ◽  
Vol 6 (2) ◽  
pp. 256-263 ◽  
Author(s):  
Andrey Danilov ◽  
Andrey Danilov ◽  
Bayana Bazhenova ◽  
Bayana Bazhenova ◽  
Michail Danilov ◽  
...  

In the current conditions of import substitution, the effective use of secondary raw materials in the meat industry is a relevant issue. A significant source of animal proteins is by-products, the yield of which is about 10% of livestock weight. Some by-products, including beef rumen, contain collagen-containing tissues which require modification for tenderization and deodorization. In order to modify rumen tissues, the biotechnological method of treatment with an enzyme solution, lysate, obtained from a whole bovine abomasum was preferred to the known method where enzyme solution is prepared from an abomasal mucosa. The purpose of this project was to study the activity of lysate from a whole bovine abomasum for the modification of rumen tissue to use it in cooked sausage formulations. We have suggested the method of obtaining enzyme solution based on infusing the minced abomasum in a reaction mixture – water, chlorohydric acid, and sodium tripolyphosphate – followed by filtering. The dependence of proteolytic and collagenase activities of the solution obtained from phosphate dose introduced have been studied; it have been revealed that 1.5% of tripolyphosphate is the optimal dose for efficient extraction of enzymes from the whole abomasum. Besides, an effect of the enzyme solution on functional and technological properties of a heat-treated rumen has been studied, and the improvement of hydro- and lipophilic characteristics has been revealed. Paste with modified rumen has been developed and found that the maximum possible dose of rumen for use in cooked sausage from horsemeat is 15%. The color on the cut of sausage developed was identical to that of beef sausage. Thus, paste made on the basis of modified rumen contributes to the formation of functional and technological properties, the stabilization of the color characteristics of the final product, as well as the effective use of basic meat raw materials and the expansion of the range of economy class high-protein sausage production.


2021 ◽  
Vol 25 (2) ◽  
pp. 48-53
Author(s):  
B.P. Yur’ev ◽  
V.A. Dudko

A technology of processing chalk from the Lebedinskoye deposit into high quality lime by roasting in a rotary kiln is proposed. A procedure has been developed for the thermodynamic calculation of the specific heat of decomposition of carbonates contained in chalk. The material and heat balances of the operating rotary kiln have been compiled. All the main parameters of its operation and the optimal fuel consumption for chalk processing have been determined.


Author(s):  
Yu. A. Zolotukhin ◽  
N. S. Andreichikov ◽  
A. Ya. Eremin ◽  
T. F. Kraskovskaya ◽  
V. V. Kuprygin

Coal raw material base of coking is the main factor characterizing the quality of coke. Therefore, it is very important to know technological properties and peculiarities of coals behavior in a charge during coking process for coals charge batching and coke quality control. One of the priority directions in study coals and charges is petrographic and reflectogram analysis, which enable to obtain data related to evaluation genuine (one-valued) technological properties of coals, coal blends and charges at production of coke of required quality. Using a broad material of study, including the one carried out by the authors of the article, a wide range of application of reflectogram analysis of coals, coals blends and charges in the coking production was shown. It was demonstrated also that application of the analysis enabled to exclude the problem of “twins”, to define the degree of genetic coals recoverability and coals grades or types relation in the mixtures for the coking. Based on the elaborated by the authors reflectogram criteria of charges for coking, a strategy of coals batching was proposed, which ensures production of metallurgical coke of required and high quality and safe running of coke ovens. Based on wide experimental studies of plastic-tough properties of coal charges, porosity of coke, its X-ray structure characteristics, strength and reaction ability, theoretical ideas were formed about mechanism of interaction in a charge of petrographically nonuniform coals comprising it during coking process, by using the proposed by the authors indices of coals nonuniformity. The indices of coals, comprising the charge, nonuniformity, differ by metamorphism degree (σR) and petrographic composition (σСК), explaining regularities of forming of quality of coke from the charge with participation of petrographically nonuniform coals. The package of the factors noted by the authors, revealed in the process of the study of coals, coals blends and charges, as well as quality of coke obtained from them, enabled to elaborate a complex index of charges coking ability (К.п.к.Vo), which enables to considerably simplify the mathematical model of coke quality prediction and to increase its reliability. Mathematical models of coke quality prediction were verified and implemented at several plants of Russia.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3041 ◽  
Author(s):  
Jiyu Wang ◽  
Kai Zheng ◽  
Na Cui ◽  
Xin Cheng ◽  
Kai Ren ◽  
...  

Lightweight aggregate concrete manufactured by solid waste or recycled by-products is a burgeoning topic in construction and building materials. It has significant merits in mitigating the negative impact on the environment during the manufacturing of Portland cement and reduces the consumption of natural resources. In this review article, the agricultural and industrial wastes and by-products, which were used as cementitious materials and artificial lightweight aggregate concrete, are summarized. Besides, the mechanical properties, durability, and a few advanced microstructure characterization methods were reviewed as well. This review also provides a look to the future research trends that may help address the challenges or further enhance the environmental benefits of lightweight aggregate concrete manufactured with solid waste and recycled by-products.


2009 ◽  
Vol 72 (4) ◽  
pp. 826-836 ◽  
Author(s):  
BERNHARD NOWAK ◽  
THEDA von MUEFFLING

The aim of this investigation was to develop a treatment for combined porcine blood corpuscle concentrate (BCC) and porcine collagenous connective tissue (rind) so as to make more use of these slaughter by-products as an ingredient in a high-quality product such as salami-type sausage. For this study, BCC was preserved, standardized (sBCC) (15% NaCl and 25% protein content), and then added (proportion of sBCC to rind, 15:85) to rind subjected to different treatments designated A, B, and C (A, 2 h at 90°C; B, 5 min at 90°C; and C, 2 h at 3°C). One half of each mixture was again heated (designated A1, B1, and C1; F70, ∼15), and the other half was only cooled (designated A2, B2, and C2). The now colored, highly proteinaceous rind mixtures (A1 to C2) were then cooled and granulated (designated GBR-A1 to GBR-C2). Three of the granulates (GBRA1, -B1, and -B2) proved to be promising new raw materials: their aerobic plate counts were <log 4.0 CFU/g, and their color was appealing (L* values, 23.9 to 25.9; a* values, 17.7 to 22.2; b* values, 11.5 to 12.7). These granulates were then substituted for part (5%) of the meat in the production of fermented raw salami-type sausages. Two of the sausages (SA1 and SB1) were microbiologically stable (containing mainly lactobacilli) and had positive sensory, chemical, and physical properties (e.g., protein, 21%; water activity, 0.90; pH, between 5.3 and 5.4 on day 36) meeting all standards for commercially produced raw sausages. Our investigation yielded a practicable way to treat and combine two slaughter by-products for use in a high-quality meat product.


2019 ◽  
Vol 121 (7) ◽  
pp. 1800513 ◽  
Author(s):  
Barbara Soldo ◽  
Vida Šimat ◽  
Jelena Vlahović ◽  
Danijela Skroza ◽  
Ivica Ljubenkov ◽  
...  
Keyword(s):  

Carbon ◽  
2011 ◽  
Vol 49 (11) ◽  
pp. 3395-3403 ◽  
Author(s):  
Ying Yang ◽  
Andrea Centrone ◽  
Liang Chen ◽  
Fritz Simeon ◽  
T. Alan Hatton ◽  
...  

2020 ◽  
pp. 33-39
Author(s):  
S. S. Plyasovitsa ◽  
◽  
O. A. Kravtsova ◽  
N. V. Ivanova ◽  
I. Yu. Semenov ◽  
...  

The authors carried out a mineralogical study and substantiated a concentration process developed for the lead-zinc ores of the Pavlovsk deposit. The concentration of the valuable component in each type of concentrate is determined by the amount of pyrite contained in the ore. It was established that the main loss of lead with flotation tailings is associated with oxidized phases, which are mainly found in fine material. Lead sulphides account for 30% of the entire waste tailings. Using the results of the mineralogical study, a flotation process was developed that involves a staged separation of commercial lead and zinc concentrates, as well as waste tailings. The obtained zinc concentrate has a consistently high quality of 57–58% with an 85–90% recovery. The metal concentration in the lead concentrate 1 is 45%, with the recovery being 43%. On the basis of the experimental results, the authors propose to use an X-ray radiometric separation method for coarse ore, which will help reduce the amount of incoming ore by 30% while minimizing the loss of lead and zinc.


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