scholarly journals Influence of Forced Carbonisation on the Binding Properties of Sludge with a High β-Belite Content

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7899
Author(s):  
Aleksandr Bakhtin ◽  
Nikolay Lyubomirskiy ◽  
Stanisław Fic ◽  
Tamara Bakhtina

Alternative binders activated by forced carbonisation are regarded as one of the potential solutions to reducing greenhouse gas emissions, water, and energy consumption. Such binders, in particular those based on nepheline sludge (a by-product of alumina production), cured in carbon dioxide with subsequent hydration, are clinkerless building materials. The development of such binders contributes to the involvement of multi-tonnage solid industrial waste in the production cycle. This type of waste is capable of binding man-made CO2 and transforming it into stable insoluble compounds, having binder properties. The optimum technological parameters of the forced carbonisation of the nepheline slime binder was determined by the mathematical planning of the experiment. The novelty of the research is the expansion of the secondary raw material base that can bind the man-made CO2 with obtaining the construction products of appropriate quality. It was revealed that the process of active CO2 absorption by the minerals of nepheline slime is observed in the first 120 min of the forced carbonization. Immediately after carbonisation, the resulting material develops compressive strength up to 57.64 MPa, and at the subsequent hydration within 28 days this figure increases to 68.71 MPa. Calcium carbonate is the main binder that determines the high mechanical properties of the samples. During the subsequent hydration of the uncoated belite, gel-like products are formed, which additionally harden the carbonised matrix. Thus, after the forced carbonisation and the following 28 days of hardening, the material with compressive strength in the range 4.38–68.71 MPa and flexural strength of 3.1–8.9 MPa was obtained. This material was characterised by water absorption by mass in the range of 13.9–23.3% and the average density of 1640–1886 kg/m3. The softening coefficient of the material was 0.51–0.99. The results obtained enables one to consider further prospects for research in this area, in terms of the introduction of additional technological parameters to study the process of forced carbonisation of nepheline slime.

2020 ◽  
Vol 315 ◽  
pp. 07008
Author(s):  
Aleksandr Bakhtin ◽  
Nikolai Lyubomirskiy ◽  
Sergey Fedorkin ◽  
Tamara Bakhtina

The paper presents research on the development of building materials with low level of CO2 emissions based on technogenic recycled materials. The paper addresses the determination of optimal formulation and technological parameters of obtaining materials based on lime dust generated by mechanical deposition in cyclones and bag filters of shaft furnaces, as well as finely dispersed marble limestone with a fraction of up to 5 mm. Studies have shown that it is possible to obtain carbonized material with compressive strength of more than 40 MPa from this recycled material by forced carbonization used during three hours. Moreover, to obtain such numbers, the optimal content of lime dust in raw materials should be in the range of 35-40% wt. when the water content of the mixture is 6-7% wt. The carbonized material obtained with the indicated technological parameters will have an average density of 1.95-2.0 g/cm3 and water absorption by weight of not more than 12%.


2020 ◽  
Vol 992 ◽  
pp. 253-258
Author(s):  
M.P. Lebedev ◽  
V.N. Tagrov ◽  
E.S. Lukin

The article deals with the manufacture of modern structural ceramic materials from clay and loam deposits of the Republic of Sakha (Yakutia). The importance and relevance of the development of the production of building materials from local raw materials is emphasized, since this will certainly affect the effectiveness of the construction complex as a whole. The successful development of the construction complex is capable of not only stimulating growth in all sectors of the economy, but also contributes to solving the most pressing social problems. Today, Yakutia has huge reserves of mineral raw materials for the production of a wide range of building materials and products. Of practical interest are wall materials made from clay soils. Given the features of the region’s raw material base, this work focuses on additional processing of traditional material. Controlling the complex physicochemical and structural-mechanical transformations that occur during heat treatment, a methodology has been developed for creating a composite material that will allow competitive innovative materials with enhanced strength properties to be produced with a reinforcing element with a glassy phase matrix of mullite crystals. The fabricated samples have a wide range of physical and mechanical properties and allow using it as a high-quality structural building ceramics, as well as industrial floor technical tile.


2020 ◽  
Vol 24 (3) ◽  
pp. 14-18 ◽  
Author(s):  
V.Z. Abdrakhimov ◽  
A.K. Kairakbaev ◽  
E.S. Abdrakhimova

The technology of obtaining clinker bricks on the basis of waste of non-ferrous metallurgy – clay part of the "tails" of the gravity of zircon-ilmenite ores and waste of energy – ash of light fraction is considered. The use of non-ferrous metallurgy and energy waste in ceramics contributes to the disposal of industrial waste, environmental protection and the expansion of the raw material base for ceramic building materials.


Author(s):  
S. Khanin ◽  
N. Kikin ◽  
O. Mordovskaya

Paddle mixers with horizontal shafts are common at building materials enterprises for the preparation of concretes, mortars, dry mortars. A new design of a horizontal paddle mixer with rod elements located in front of the working surfaces of the blades, changing the trajectories of material particles, increasing their mobility, which leads to an increase in the degree of homogeneity of the mixed material, is considered. The aim of the study was to assess the influence of rod elements on the quality of preparation of a cement-sand mixture, to establish patterns of influence on it by the design and technological parameters of a two-shaft paddle mixer and to determine the areas of their rational values. The following tasks have been solved. A bench installation of a two-shaft horizontal paddle mixer with rod elements has been developed, on which experimental studies have been carried out on the preparation of dry cement-sand mixtures. For the criterion characterizing the quality of the mixture, the ultimate compressive strength of the prism specimens made from it is adopted. Regression equations are obtained that adequately describe the compressive strength of prism samples from the design and technological parameters of the mixer: the angle of the blades, the distance from the working surfaces of the blades to the rod elements, the rotational speed of the blade shafts, and their analysis is performed. The analysis of the change in the ultimate compressive strength of the prism specimens from the parameters under study is carried out, the rational ranges of their values are determined. It was found that a mixer with rod elements allows to obtain a dry cement-sand mixture, products from which have a higher compressive strength. During the work, the method of mathematical planning of experiments was used. As a result of the study, an assessment of the influence of rod elements on the quality of preparation of a cement-sand mixture was carried out, the regularities of the influence on it of the design and technological parameters of a two-shaft paddle mixer and the area of their rational values were established.


Author(s):  
V. I. Tischenko ◽  
N. V. Bozhko ◽  
V. M. Pasichnyi ◽  
V. V. Brazhenko

Creation of combined meat products combining traditional consumer properties, as well as the possibility of using non-traditional raw materials in their recipes, is aimed at the expansion and rational use of the raw material base of the meat processing complex and solves the problem of reducing nutrient deficiency in the diet of the population. Therefore, the issue of the use of mechanically deboned poultry meat in meat bread technology and its impact on qualitative indicators and functional and technological properties is relevant. The aim of the research was to study the feasibility of the use of mechanically deboned poultry meat in the technology of combined products. Three model recipes based on the formula-meat analogue “Chainyyi” were developed. The possibility of replacing beef and pork meat with duck meat and mechanically deboned poultry meat of turkey was studied in the bread recipes. The total amount of duck meat and mechanically deboned poultry meat was 63%. As a protein ingredient able to bind moisture and relatively inexpensive compared to meat raw material, 20% of the pig's heart was added to the formulation, as well as 2% XB Fiber. Other components of the analogue formulation have not changed. Combination of duck meat with mechanically deboned poultry meat of turkey and pork hearts in the abovementioned ratios as part of meatcontaining bread stuffing systems allowed to improve the nutritional value of the product and its qualitative indices. The research confirmed the possibility of combining regional and relatively cheap raw materials to increase the nutritional value of meatcontaining products, namely breads. The bulk of proteins in the experimental samples increased by 6.57–10.38% and was within the range of 17.96–17.34%. On average, 4.98% decreased the fat content, the product became less calorie relative to the analogue by 15.98–16.76%. The formulations of model minced meat were distinguished by a higher index of the water-holding capacity, the content of binding moisture and the best indicators of plasticity. This affected the quantity of finished products, which amounted to 120.64–117.3% to the mass of raw materials, while in the control sample this figure was lower by 3.49–7.47%.


2018 ◽  
Vol 20 (90) ◽  
pp. 22-26
Author(s):  
Y. Matsuk ◽  
I. Marchenko ◽  
V. Pasichnyi

The article is devoted to the improvement of the recipes of minced meat products with using fish raw materials and the study of organoleptic and functional and technological properties of developed minced meat systems and finished products. The research has been carried out on the rational combining of meat and fish raw materials and the expansion of assortment of minced semi-finished products. The formulations of minced meat systems for the production of meat semi-finished with a partial replacement of the main raw material to fish raw materials have been developed. The organoleptic and functional and technological parameters of minced meat systems and finished products are investigated. According to the results of the organoleptic evaluation, it was found that partial replacement of meat raw material with minced fish does not worsen the sensory characteristics of minced meat products. It is established that in comparison with the control sample there is an improvement of functional and technological indicators. In particular, the moisture content increased by an average of 6.1%, moisture absorption capacity – 5.91%, energy absorption capacity – 2.49%, fat-retaining ability – 2.52%. The obtained results confirmed the expediency of using minced meat with pollack in the technology of minced meat semi-finished products with due observance of the parameters of production cycle of heat treatment of products. It has been theoretically substantiated and experimentally confirmed the technology of meat products using minced meat and developed recipes. It has been established that with careful selection of components that are part of minced meat semi-finished products with the addition of fish raw materials can increase the organoleptic and functional and technological parameters of finished products. The obtained data suggest that the improved recipes of minced meat semi-finished products can be recommended for production by enterprises of the meat industry and restaurants


Author(s):  
Mauricio H. Cornejo ◽  
Jan Elsen ◽  
Bolivar Togra ◽  
Haci Baykara ◽  
Guillermo Soriano ◽  
...  

Mordenite-rich tuff is one of most available zeolitic rocks all over the world. Because of this, the research of natural mordenite as a raw material of geopolymeric materials can provide an almost unlimited source of solid precursor for manufacturing such building materials. Despite efforts to shed light on the behaviour of mordenite-rich tuff during geopolymeric reaction, the performance of these novel materials is barely understood. The aim of this study is to explore the effect of the content of calcium hydroxide, CH, and water-to-solid ratio, W/S, as mixing parameters on compressive strength of mordenite-based geopolymers, MBG, and its thermal conductivity. As solid precursor was used mordenite-rich tuff and mixed with sodium hydroxide (NaOH) at 10M that kept constant during the experiment. Two experimental parameters were selected as independent variables i.e, the content of CH and water-to-solid ratio, and their levels, according to a central composite experimental design. All these designed mixes were characterized by using quantitative X-ray diffraction (QXRD), Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetry and differential scanning calorimetry (TGA-DSC), scanning electron microscopy coupled with energy dispersed spectroscopy (SEM-EDS), in addition thermal conductivity tests were also run according to standard method ASTM C177 at 9, 24, 39°C. The overall results suggested that MBG can be used as building material, however its thermal conductivity was higher than that of commercial isolate building material. The experimental design analysis indicated that the optimum water-to-solid ratio was 0.35, but in the case of the content of CH, the optimum value was not observed on this experimental range because the compressive strength increased as the content of CH increased as well. The compressive strength of MBG was observed in the range between 8.7 and 11.3 MPa. On the other hand, QXRD and FTIR showed that mordenite reacted during the geopolymeric reaction, but instead quartz, also found in zeolitic tuff, acted as inert filler.


Buildings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 67 ◽  
Author(s):  
Jolanta Harasymiuk ◽  
Andrzej Rudziński

The use of industrial residues to replace natural resources for the production of building materials is economically and ecologically justified. Fly ash (FA) taken directly from electro-filters is commonly used as a cement replacement material. This is not the case, however, for old dumped fly ash (ODFA) that has been accumulating in on-site waste dumps for decades and currently has no practical use. It causes environmental degradation, which is not fully controlled by the governments of developed countries. The aim of the study was to assess the possibility of using ODFA as a partial replacement for sand in cement composites. ODFA replaced part of the sand mass (20% and 30%) in composites with a limited amount of cement (a cement-saving measure) and sand (saving non-renewable raw material resources). ODFA was activated by the addition of different proportions of hydrated lime, the purposes of which was to trigger a pozzolanic reaction in ODFA. The quantitative composition of the samples was chosen in such a way as to ensure the maximum durability and longevity of composites with a limited amount of cement. The 28-day samples were exposed to seawater attack for 120 days. After this period, the compressive strength of each sample series was determined. The results suggest the possibility of using ODFA with hydrated lime to lay town district road foundations and bike paths of 3.5 to 5 MPA compressive strength. What is more, these composites can be used in very aggressive environments.


2018 ◽  
Vol 7 (3.2) ◽  
pp. 501
Author(s):  
Mustafa Baba Babanli ◽  
Liubov Shumska ◽  
Maryna Leshchenko

The work is devoted to theoretical and experimental research of thermophysical features of the creation of new porous heat insulating materials, precisely: research of thermodynamic parameters of the heating processes, swelling and drying of materials; substantiation of the choice of the raw mixture method formation and determination of the optimal energy parameters of the swelling process; development of mathematical models of material heat treatment process and methods of basic technological parameters determination; development of advanced technologies for thermal protection of buildings and power equipment. Experimentally determined dependencies of technological parameters of heat treatment of the raw material mixture in the discharge, its composition, which allows obtaining material with minimal thermal conductivity. Also, the resulting dependencies ensure to find the required mode of heat treatment for the given thermophysical properties. The experimental setup has been developed, which provided to determine the basic laws of heat transfer of porous material, on the basis of which data were obtained, which allow to carry out an estimation of heat transfer and exchange characteristics of the new dispersed porous material necessary for technological calculations. A complex mathematical model of the heat energy mode of the building was created, as well as a program for solving the equations of this model, which makes it possible to determine the basic energy characteristics.  


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