64   A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture                   www. grnjournal.us  

 
 

AMERICAN Journal of Engineering,  
Mechanics and Architecture 

Volume 01, Issue 07, 2023 ISSN (E): 2993-2637 

 
  

Physico-Chemical Processes for the Production 

of Agloporite From Industrial Waste in Uzbekistan 
 

Shakirov Tuyg’unjon Turg’unovich
 

Candidate of Technical Sciences, Associate Professor, Head of the Department  

of TCM and IC Tashkent University of Architecture and Civil Engineering 

Odiljanov Azimbek Zokirjon o’g’li
 

Doctoral student of the Department of TCM and IC department Tashkent University  

of Architecture and Civil Engineering 

 

Abstract: The possibility of obtaining high-quality porous agloporite material with high physical 

and mechanical properties based on local clay raw materials and industrial waste from the 

Tashkent industrial region has been established. The effect of chloride roasting, whose 

components are phosphogypsum industry waste and alkaline soda waste, on the mechanism and 

kinetics of mineral formation during agglomeration of agloporite gravel, is studied. It was 

established that the used waste - mineralizers accelerate the process of glass formation during 

chloride firing, reducing the temperature of agglomeration and pressing by 50-80 
o
С, while 

obtaining a durable porous material. The regularities of the influence of physicochemical 

features, used clay materials and flotation waste of the Almalyk mining and smelting complex on 

the mechanism of mineral and pore formation during agglomerate agglomeration are revealed..  

Keywords: agloporite, physicochemical properties, mechanism, kinetics, expansion, chloride 

firing. 

 

Introduction 

During the enrichment of metallurgical ores, a huge amount of waste is generated. No other type 

of human industrial activity affects the environment as extensively and destructively as mining. 

In the sphere of its direct influence are the water and air basins, the earth's surface, subsoil, fauna 

and flora - all elements of the natural environment. On the other hand, in the process of mining 

and processing of minerals, a significant amount of various wastes of direct production is 

generated, which often significantly exceeds the mass of marketable products. Therefore, their 

integrated use is not only the basis of waste-free production, but also serves as a radical means of 

reducing the technogenic load on the natural environment and an important source of saving 

labor and natural resources. 

The economic significance of the problem of using secondary material resources lies in the fact 

that its correct solution allows: increasing the types of raw materials, reducing the use of natural 

raw materials; to prevent the loss of a large amount of land, including those important for 

agricultural production, which are occupied by dumps for waste and by-products; avoid high 

costs for the creation of warehouses, storage facilities, dumps; improve the technical and 

economic indicators of industries. 

The use of waste and by-products in the building materials industry gives a great economic effect 

due to a reduction in the cost of production, fuel, electricity and capital costs. Raw materials or 



 

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components that are made from waste are cheaper than raw materials that are made specifically 

from natural materials. Current investments in the use of certain types of waste are reduced by 

(30–50%). In addition, it should be remembered that the known reserves of natural raw materials 

are increasingly depleted and moving away from industrial regions. 

At present, much attention is paid to energy saving issues. One of these areas is the use of 

building materials with thermal insulation properties. Agloporite is widely used as a heat-

insulating material for the manufacture of lightweight concrete and heat fillings. 

Agloporite is a porous granular material of a cellular structure obtained by swelling of clay rocks 

during their firing. Complex physical and chemical processes occur in the fired clay material in 

different temperature ranges: dehydration, burnout of organic impurities, interaction between 

clay components, redox reactions, and others, which causes gas evolution, melt formation, 

softening of the material. With rapid firing, the temperature intervals approach, shifting to the 

region of high temperatures, which makes it possible to combine the process of gas formation 

with the softening of the material and the achievement of a certain viscosity, at which the clay 

swells. In this case, it is important that by the time of intense gas evolution, the surface layer of 

the granules should be sintered with the formation of closed pores. Otherwise, the gases are 

easily removed through the layer of material without swelling it. 

According to the degree of swelling, weakly, medium, and well-swelling clayey rocks are 

distinguished with a swelling coefficient of at least 2.5, respectively, or from 2.5 to 4.5 and 

higher. 

The existence of different opinions about the causes of swelling and pore formation in clay raw 

materials during its high-temperature heat treatment to obtain agloporite and the inconsistency of 

some of these opinions indicate insufficient knowledge of the main factors of swelling and pore 

formation (1-4). 

In this paper, we studied the possibility of obtaining a heat-insulating material - agloporite based 

on the use of technogenic products, by recycling various industrial wastes, as well as overburden 

clayey rocks and studying the effect of their physical and chemical properties on the mechanism 

and patterns of formation of porous agloporite. 

For this purpose, clay materials and flotation wastes of the Tashkent industrial region were 

considered as raw materials in the production of aggloporite. 

Research methods and materials used 

According to the results of preliminary studies, it was found that the most accessible and suitable 

materials for these purposes are overburden clay rocks of the Akhangaran deposit of loess and 

gray unenriched kaolin of the Angren coal basin, and as the main aluminosilicate component, the 

flotation tailings of the lead and copper processing plants of the Almalyk Mining and 

Metallurgical Plant (5,6) . As mineralizers of agglomeration and swelling processes, and as a 

chlorinator of residual metals contained in tailings, solid alkaline waste from soda production 

and phosphogypsum - waste from phosphoric acid production were used. 

Table 1. The chemical composition of the materials used 

Names SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O SO3 Ppp 

Floating waste MOF 59,32 13,86 9,31 1,16 0 2,31 3,14 6,02 4,18 

Flotation waste SOF 45,7 8,72 7,1 14,59 7,10 2,00 0.98 2,98 8,83 

Unenriched kaolin 58,6 18,95 1,87 3,91 0,53 0,12 1,11 0,12 14,72 

Less 49,29 11,66 4,41 13,97 3,28 1,44 0,80 1,30 13,29 

Phosphogypsum 10,43 0,420 0,15 28,32 - 0,04 0,04 40,51 19,64 

Waste TOSP 1,1 0,4 - 47,1 4,2 - - 3,8 42,40 

 



 

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The study of the used components of raw mixtures was carried out by a number of physical and 

chemical methods of analysis: X-ray phase, petrographic and infrared - spectroscopic, 

mineralogical. 

X-ray phase analysis of the materials used showed differences in their chemical and 

mineralogical composition, which certainly indicates a completely variable effect on the 

processes of solid-state transformations occurring during firing, the temperature of the onset of 

the formation of the liquid phase and swelling of aggloporite, on the degree of swelling and a 

number of other physicochemical processes occurring during the agglomeration of silicate 

mixtures. 

The flotation waste from the copper concentrating plant (MOF) - dark gray in color, is formed 

during the enrichment of copper-bearing ore, it is an aluminum-iron silicate substance. The 

results of chemical analysis of flotation waste samples showed their little changeable chemical 

composition. The samples are characterized by a high content of silica, reaching 63% and its 

melting point is 1220-1240 
o
C. 

 

Figure 1. X-ray patterns of flotation wastes: a) MOF-copper-concentrating and b) SOF of the 

lead concentrator 

The main minerals are quartz (up to 40%), feldspar (10%), hydromica (23%) and a small amount 

of calcium and magnesium carbonates. X-ray patterns of the MOF flotation waste burned at 

different temperatures show characteristic maxima of quartz d=0.3344; 0.181; 0.153 nm, feldspar 

d=0.200; 0.166 nm, hydromicas d=0.441; 0.254; 0.148 nm, hematite d=0.370; 0.471; 0.499 nm, 

gelenite d=0.247; .284; 0.364 nm. 

Dump tailings of the lead concentration plant (SOF) of the Almalyk Mining and Metallurgical 

Combine are formed during the flotation enrichment of lead-containing ore and are a free-

flowing, sandy material of gray color, with a grain size of 1-3 mm and a moisture content of 3-

5%. The main constituents of tails are; oxides of silicon, calcium, aluminum and magnesium 

with the following mineralogical composition: quartz, calcite, dolomite, feldspar. As noted in a 

number of studies (7-10), clays containing silica in an amount exceeding 65% are in most cases 

unsuitable for the production of agloporite and expanded clay. As the content of SiO2 increases 

and the content of Al2O3, Fe2O3, MgO, Na2O K2O decreases, the swelling of clayey rocks 

decreases. A feature of the chemical composition of the studied clays is a low content of iron 



 

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oxide - up to 5%. The granulometric composition of the clays of these deposits are similar and 

are characterized by a low content of large particles (1-0.005 mm), a high content of silty 

particles (0.05-0.005 mm) and a low content of particles of fine fractions. At the same time, the 

granulometric composition of flotation tailings differs in particle size from the natural clays 

used. The degree of swelling is greatly influenced by all oxides contained in clays and flotation 

tailings, so the optimal content should be, according to some studies, in the range of 17-22%, as 

the alumina content decreases, the swelling of clays decreases sharply. Also in the works (7,8) it 

was found that as the ability to swell in clay materials decreases, the content of MgO decreases 

markedly, the introduction of which in the composition of alkaline waste from soda production 

causes, as shown further, their swelling during chloride firing. In addition, it is known that an 

increase in the CaO content above 3-4% sharply worsens the sintering of granules during firing, 

and the content of alkaline oxides of potassium and sodium above 3-4% increases the swelling of 

the granules. A number of scientific data (9, 10) have shown the dependence of the 

physicomechanical parameters of aggloporite on the physicochemical properties of the raw 

materials used, when the optimal chemical and mineralogical composition of the raw mixture 

makes it possible to greatly reduce the temperature of formation of the liquid phase and firing 

and increase pore formation and strength characteristics. Summarizing the above, it should be 

noted the possibility of using the proposed rocks and waste as a raw material for the production 

of agloporite. 

Experimental Raw materials were first dried and ground in a laboratory ball mill to a specific 

surface area of 1300-1500 g/cm2. Then the components were weighed in the required quantities 

and mixed dry. After that, water was added to the dry mixture. Granules 10-15 mm in diameter 

were made from the resulting mixture and fired in an electric muffle furnace with silicate heaters 

to temperatures of (1000, 1100, 1200) °C. 

Physical and chemical studies have established that raw mixtures with MOF flotation waste have 

a higher swelling ability compared to mixtures based on SOF flotation waste, while at the same 

time, from clay materials, kaolin from the Angren deposit is also preferable in comparison with 

the forest of the Akhangaran deposit in terms of its chemical and mineralogical properties. 

characteristics. The temperature of the beginning of the formation of the glass phase and the 

completion of the agglomeration of raw mixtures based on the flotation wastes of MOF and SOF 

with the addition of wood and kaolin clay as an intumescent material, without mineralizers and 

with their participation, was determined, as a result of which the regularities of the influence of 

the physicochemical properties of the components on the agglomeration process were 

established. It is shown that the temperature of the beginning of swelling of aggloporite, and this 

process itself is directly dependent on the chemical and mineralogical composition of the initial 

components, so unenriched kaolin significantly increases the swelling of aggloporite. Therefore, 

further studies were carried out in mixtures with unenriched kaolin (Table 2). 

Table 2. Compositions of the studied raw mixes for agloporite 

Raw mix № Kaolin HMOF waste SOF waste Coal Phosphogypsum 

1 10,0 85,0 - 5,0 20,0 

2 15,0 80,0 - 6,0 30,0 

3 20,0 73,0 7,0 30,0 30,0 

4 10,0 - 5,0 15,0 30,0 

5 15,0 - 80,0 6,0 30,0 

6 20,0 - 73,0 7,0 30,0 
 

Chloridny objig syrevyx smesey providolsya v temperaturennom intervale 1000-1200 oS, c 

dobavkoy ot 10 do 30% phosphogypsa i schelochnogo othoda, v vide granule 10-15mm mixed v 

corundum tygli. In the case of conducted experiments, it was established that the temperature of 

the appearance of the glass phase and the final agglomeration of 50-100 °C in the sulfochlorite 

objige occur, and the resulting material has a pronounced porosity. 



 

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Figure 2. X-ray patterns of obtained aggloporites a) based on SOF flotation waste, b) based on 

flotation waste MOF with sulfochloride additive 30% alkaline waste + 30% phosphogypsum 

X-ray phase and petrographic methods have been used to study the effect of sulfochloride 

roasting on the mechanism and kinetics of agglomeration of agglomeration crushed stone, and it 

has been shown that at a temperature of 800-900 
o
C in raw mixtures, decomposition of the initial 

minerals - feldspars with d=0.200; 0.166 nm, hydromica with d=0.441; 0.254; 0.148 nm, CaCO3 

with d=0.303; 0.191; 0.187 nm with the formation of new mineral phases in mixtures with MOF 

tails at Tobf=950-1100 
o
C mullite with d=0.211; 0.220; 0.339 nm, gelenite c d=0.285; 0.243 nm, 

calcium aluminate with d=0.297; 0.252 nm, in agloporite with SOF tails additionally 

okkermanite with d=252 nm, wollastonite with d=0.329 nm (Fig. 2). 

When determining the temperature range of sintering and swelling for mixtures of unenriched 

kaolin with flotation waste from a copper concentrating plant, the best results were obtained for 

samples from Angren unenriched kaolin with the addition of alkaline waste from soda 

production and phosphogypsum in various amounts; Tobzh 1160-1190 
o
C and with the addition 

of 30% alkaline waste and 30% phosphogypsum, there is a decrease in T obzh. up to 1100-1140 
o
C, and the swelling coefficient of agloporite increases from 2.5 to 3.5 (Table 3). The coefficient 

of swelling of clay raw materials without additives and with additives is determined as the ratio 

of the volume of an expanded granule to the volume of a semi-finished product granule. The 

volume of each grain of a semi-finished product of stone-like raw materials, expanded clay 

crushed stone and gravel is determined according to GOST 9758 and calculated by the formula 

. 

The coefficient of swelling of clay raw materials is determined by the formula 

 

where is the  sum of the volumes of granules (grains) of the semi-finished product supplied 

for expansion, cm; - the sum of the volumes of expanded granules of expanded clay gravel 

and expanded clay crushed stone, see. 

 



 

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Table 3.The swelling temperature of optimal formulations 

Compounds 

№ 

Composition of components in% 

Т
o
С 

Coefficient 

To, 

swelling 
Kaolin 

HMOF 

waste 

SOF 

waste 
Coal SHOSP Phosphogypsum 

1 10 85 - 5 20 20 1130 2,9 

2 15 80 - 7 30 30 1110 3,6 

3 20 75 - 6 20 30 1120 3,2 

4 10 - 85 5 20 20 1150 2,7 

5 15 - 80 7 30 30 1140 3,1 

6 20 - 75 6 20 30 1145 3 
 

Presumably, on the basis of the physical and chemical studies carried out, the reaction 

mechanism during the synthesis of agloporite with flotation waste MOF and SOF proceeds 

according to the following scheme, at a temperature of 900-1000 
o
C, dehydration of clay 

minerals and iron hydroxide and crystallization of hematite and gelenite occur. At these 

temperatures, processes occur in the material, the most important for the formation of the 

structure of agloporite. 

Inside the layer, with a lack of oxygen, the environment is reducing, therefore ferrous oxides are 

reduced to FeO, which contributes to the intensive formation of the liquid phase, in addition, a 

sulfochloride additive serves as a smooth decrease in the temperature of the formation of the 

liquid phase, resulting in a decrease in the agglomeration completion temperature by 50-80 
o
C. 

Sintering occurs inside the granules and at their contacts. The loose layer turns into sintered, but 

porous due to the suction of gases. Clay and mica impurities partially swell, causing the 

formation of a certain proportion of closed pores in the material. 

It has been established that the used mineralizers accelerate the process of glass formation during 

sulfochloride firing, reducing the agglomeration temperature by 50-80 
o
C, obtaining a durable 

porous material. Regularities of the influence of physical and chemical features of the used clay 

materials and flotation tailings of the Almalyk Mining and Metallurgical Plant on the mechanism 

of mineral and pore formation during sulfochloride roasting are revealed. As a result of the 

experiments, materials were identified that meet the requirements for chemical and mineralogical 

composition to obtain aggloporite with such properties as a high degree of pore formation, 

strength and low agglomeration temperature. Raw mixtures of unenriched kaolin and flotation 

waste from a copper processing plant (MOF) with the integrated use of phosphogypsum 

agglomeration process and alkaline waste from soda production as a mineralizer, which, as 

established by a complex of physicochemical methods, positively affect the kinetics of 

agglomeration and pore formation of aggloporite crushed stone. 

It has been established that raw mixtures based on MOF flotation waste have a higher swelling 

capacity compared to mixtures based on SOF flotation waste. 

List of used literatures: 

1. A practical methodological manual for the production of heat-retaining building materials 

based on vermiculite. “Ўзсаноатқурилишбанк” ATB-2021. 

2. ГОСТ 7076-99 “Building materials and products. Method for determining thermal 

conductivity and thermal resistance in a stationary thermal regime”. 

3. Ganiev A., Tursunov B., Karshiev E. Study of physical and mechanical properties of high 

strong concrete with chemical additives //AIP Conference Proceedings. – AIP Publishing 

LLC, 2022. – Т. 2432. – №. 1. – С. 050046. 

4. Akramov X. A. et al. To Produce an Effective Composition of Vermiculite Plita and to Study 

the Coefficient of Thermal Conductivity //The Peerian Journal. – 2022. – Т. 8. – С. 29-37. 



 

70   A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture                   www. grnjournal.us  

 
 

5. Ganiev A., Tursunov B. A., Kurbanov Z. K. Prospects for the use of multiple vermiculitis 

//Science and Education. – 2022. – Т. 3. – №. 4. – С. 409-414. 

6. Khursanovich T. F., Orologli N. I. The study of physical and mechanical properties of 

construction gypsum and its study on the construction //ACADEMICIA: An International 

Multidisciplinary Research Journal. – 2020. – Т. 10. – №. 5. – С. 1990-1995. 

7. X.Akramov, Sh.Raximov, X.Nuritdinov, M.Turopov “Beton to„ldiruvchilari texnologiyasi” , 

O„quv qo„llanma, Toshkent, 2012y. 

8. Gaziev U.A., Kadirova D.Sh. Beton va qorishmalar uchun qo„shimchalar. O„quv qo„llanma. 

2015.