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CHEMICAL SCIENCES
FLOTATION ACTIVITY OF ALIPHATIC AMINE SYNTHESIZED BASED ON INDUSTRIAL WASTE
1 2 3
Bukhorov Sh.B. , Eshmetov I.D. , Adizov B.Z. (Republic of Uzbekistan) Email: [email protected]
1Bukhorov Shukhrat Burievich - Candidate of Chemical Sciences, Associate Professor, DEPARTMENT OF GENERAL CHEMISTRY, TASHKENT CHEMICAL TECHNOLOGICAL INSTITUTE;
2Eshmetov Izzat Dusimbatovich - Doctor of Technical Sciences, Professor, Head of the Laboratory;
3Adizov Bobirjon Zamirovich - Doctor of Technical Sciences, Leading Researcher, COLLOIDAL CHEMISTRY LABORATORY, INSTITUTE OF GENERAL AND INORGANIC CHEMISTRY ACADEMY OF SCIENCES OF THE REPUBLIC OF UZBEKISTAN, TASHKENT, REPUBLIC OF UZBEKISTAN
Abstract: in this work, studies of the conditions affecting the flotation of potassium chloride from model solutions are given. Model solutions were prepared with 3 different concentrations, in which the mass ratio of NaCl and KCl is: 1:1 (P1); 1: 0.5 (P2) and 1: 0.25 (P3), and the total salt content in the solution does not exceed 50%. Therefore, for the flotation of sylvinite ores with a mass content of the main required component of more than 20%, the required amount of this amine is more than 10 g per ton of ore. As a result of an increase in the temperature of the solution from 20 to 30 °C, an increase in the degree of KCl extraction from Р3 by 20% is observed. An increase in temperature causes a noticeable displacement of the extremum of extraction of clay substances to higher values of the collector flow rate, and of non-clay substances, on the contrary, in the opposite direction of values along the horizontal axis. Thus, in order to ensure the maximum recovery of insoluble impurities into the flotation sludge product, the determining factor is the choice of the optimal flocculant flow rate at the base flow rate of the sludge collector.
Keywords: flotation, aliphatic amines, adsorption, critical micelle concentration (CMC), Kraft point, surfactants (surfactants), cloud point, clay impurities, non-clay impurities, potassium chloride, potash ores.
ФЛОТАЦИОННАЯ АКТИВНОСТЬ АЛИФАТИЧЕСКОГО АМИНА, СИНТЕЗИРОВАННОГО НА ОСНОВЕ ПРОМЫШЛЕННЫХ ОТХОДОВ Бухаров Ш.Б.1, Эшметов И.Д.2, Адизов Б.З.3 (Республика Узбекистан)
1Бухоров Шухрат Буриевич - кандидат химических наук, доцент, кафедра общей химии, Ташкентский химико-технологический институт;
2Эшметов Иззат Дусимбатович - доктор технических наук, профессор, заведующий лабораторией;
3Адизов Бобиржон Замирович - доктор технических наук, ведущий научный сотрудник, лаборатория коллоидной химии, Институт общей и неорганической химии Академия наук Республики Узбекистан, г. Ташкент, Республика Узбекистан
Аннотация: в данной работе приводятся исследования условий, влияющих на флотацию хлорида калия из модельных растворов. Приготовлены модельные растворы с 3 различными концентрациями, в которых массовое соотношение NaCl и KCl составляет: 1:1 (Р1); 1:0,5 (Р2) и 1:0,25 (Р3), а общее содержание солей в растворе не превышает 50%. Следовательно, для флотации сильвинитовых руд с массовым содержанием основного необходимого компонента более 20% необходимое количество данного амина составляет более 10 г на тонну руды. В результате увеличения температуры раствора от 20 до 30°С наблюдается повышение степени извлечения KCl из Р3 на 20%. Повышение температуры вызывает заметное смещение
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экстремума извлечения глинистых веществ к более высоким значениям расхода собирателя, а неглинистых веществ, наоборот, в обратную сторону значений по горизонтальной оси. Таким образом, для обеспечения максимального извлечения нерастворимых примесей во флотационный шламовый продукт определяющим фактором является выбор оптимального расхода флокулянта при базовом расходе собирателя шламов.
Ключевые слова: флотация, алифатические амины, адсорбция, критической концентрации мицеллообразования (ККМ), точка Крафта, поверхностно-активные вещества (ПАВ), точка помутнения, глинистые примеси, неглинистые примеси, хлористый калия, калийные руды.
The flotation activity of amines is indirectly characterized by the amount of adsorption of their molecules on mineral crystals and the turbidity of its aqueous solution, which depends on the solubility, as well as the critical micelle concentration (CMC) [1].
In aqueous solutions of aliphatic amines at very low concentrations corresponding to the critical micelle concentration (CMC), spherical micelles are formed containing from 20 to 100 molecules and characterized by a narrow particle size distribution. Micelle formation occurs in a certain temperature range for each surfactant, the most important characteristics of which are the Kraft point and the cloud point [2, 3].
The Kraft point is the lower temperature limit of micelle formation of ionic surfactants, in most cases it has values within the temperature range of 10-20°С. It is known that at low temperatures of the Kraft point, the solubility of surfactants is insufficient for the formation of micelles [4].
Cloud point - the upper temperature limit of micelle formation usually having values within the temperature range of 50-60°C, and at higher temperatures, the system consisting of surfactant molecules and solvent loses stability and stratifies into two macrophases. It is known that at concentrations below the CMC, the amount of surfactant is insufficient for the formation of stable adsorption layers on the surface of minerals, and in the opposite case, the adsorption layers are characterized by low mobility, fragility and instability due to the transition of a micelle from one form to another (cylindrical, disk-shaped) [5, 6].
With a change in temperature, for solutions of aliphatic amines, a shift in CMC is characteristic; accordingly, the actual task was to determine this point for the synthesized amines in the temperature range of 10-45 ° C.
In this work, studies of the conditions affecting the flotation of potassium chloride from model solutions are given.
Model solutions were prepared with 3 different concentrations, in which the mass ratio of NaCl and KCl is: 1:1 (P1); 1: 0.5 (P2) and 1: 0.25 (P3), and the total salt content in the solution does not exceed 50%.
To prepare solutions, the salts, dried to constant weight at a temperature of 120 ° C, were quantitatively transferred into volumetric flasks with a capacity of 1000 cm3, dissolved in distilled water, bringing the solution to the mark. Experimental flotation processes were carried out on an FML 240 flotation machine. The consumption of aliphatic amine for all samples was 10 mg per kg of salt mixture. The research results are shown in table. 1.
Table 1. Results offlotation of model solutions at 22 ± 1 °C using an aliphatic amine
Model solutions
Index Р1 Р2 Р3
Output, %:
Concentrate 41,2 30,5 19,6
tail 58,8 69,5 80,4
Mass fraction of KCl,%:
Concentrate 97,2 91,3 90,8
tail 17,0 7,8 4,3
KCl recovery,%:
Concentrate 80 83,6 89
tail 20 16,4 11
As shown in the table. 1. a decrease in the concentration of potassium chloride in the mixture, leads to an increase in the yield of its extraction from this mixture. Probably, the lower recovery factor P1 is associated with insufficient amounts of amine for adsorption of its molecule on the entire surface of the floated material. Under the influence of amine, P3 floats more fully, which indicates sufficient collector amounts. Therefore, for the flotation of sylvinite ores with a mass content of the main required component of more than 20%, the required amount of this amine is more than 10 g per ton of ore (this amount is calculated using the CMC value).
It is generally known that temperature will be a key factor in the flotation of potassium chloride from sylvinite ore. An increase in temperature will have a greater effect on the solubility of potassium chloride than sodium chloride. Consequently, an increase in temperature favors an increase in the yield of flotation processes. In fig. 1 shows curves characterizing the effect of temperature on the degree of extraction of potassium chloride from the mixture.
Fig. 1. Change in the degree of extraction of KCl from P3 from temperature
As the curves of the diagram show, as a result of an increase in the solution temperature from 20 to 30 ° C, an increase in the degree of KCl extraction from P3 by 20% is observed. A decrease in this indicator with a further increase in temperature is associated with the structural features of surfactants and an increase in the fraction of their desorption at the interface.
As shown by the research results, the optimal temperature for extracting KCl from model solutions using the developed amine fluctuates in the temperature range 22 <35°C.
Industrial practice has shown the negative effect of water-insoluble impurities on the flotation ability of potassium chloride, reducing the recovery of KC1 into concentrate. The negative effect of this mixture increases significantly with an increase in the total content of silicate minerals in them. The silicate mineral component means clay silicates (kaolin, hydromica, and non-clay silicates (quartz, feldspar), which differ significantly in their sorption activity. The presence of traces of clay minerals leads to overconsumption of collectors' reagents, in our case amine, because impurities of clay minerals are excellent sorbents in relation to surfactants. This situation leads to a deterioration in the quality of the concentrate and an increase in the negative effect of water-insoluble impurities on the entire technological process of KCl flotation.
Therefore, studies have been carried out on the influence of n.d. at different temperatures and its composition on the degree of extraction KC1.
The sorption activity of all constituent components of the insoluble impurity increases with increasing temperature, thereby impairing the floatability of sylvite.
Fig. 2. The influence of the amounts of NO. in the composition of the model solution P3 on the relative decrease in the degree of extraction KC1 (20 ± 1 °C): 1) clay impurities; 2) non-clay impurities; 3) clay impurities and non-clay impurities in a mass ratio of 1:1
Fig. 3. Influence of solution temperature and composition of n.d. in an amount of 5% by weight of salts for a relative decrease in the degree of extraction of KC1: 1) clay impurities; 2) non-clay impurities; 3) clay
impurities: non-clay impurities in 1:1
Thus, a non-clayey mineral consisting mainly of clay and only non-clay minerals in an amount of 1% in the composition of the P3 mixture causes a decrease in the degree of recovery of KC1 by 64 and 17%, respectively. These data were obtained at a mother liquor temperature of 20 ± 1°C. An increase in temperature to 35 ° C leads to an extreme decrease in the degree of recovery of the main component. In fig. 2 shows the results of a study of the influence of the amount and composition of n.d. on the floatability of KC1 from model solutions.
An increase in temperature from 20 to 40° C will have a strong effect in the case of content in N.O. clay minerals and, to a lesser extent, non-clay impurities. In this and other case, the presence of n.d. will negatively affect the degree of concentration of mineral ores. The possibilities of neutralizing or mitigating the negative actions of the n.d. were investigated. with a change in the concentration of the introduced collector. As a result, it was found that the amount of insoluble impurities determines the optimal consumption of reagents. The dependence of the recovery of the insoluble residue into the frothy product of the flotation of the sludge on the flow rate of the flocculant is shown in Fig. 4. In contrast to the nature of the influence of the flow rate of the flocculant on the floatability of the main component, an increase in the flow rate of the collector
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activates the flotation of n.d. up to a certain limit, after which an increase in the collector consumption does not cause abrupt changes in the recovery of n.d. into a foam product.
Fig. 4. Influence of the collector consumption on the recovery of n.d. in the concentrate (content of n.d. 5% of the mass of the mixture, solution temperature 22 ± 1 С: 1) clay impurities; 2) non-clay impurities; 3) clay
impurities: non-clay impurities in 1:1
As the curves of the diagram show, the dependence of the extraction of the insoluble residue into the concentrate on the consumption of the flocculant has an extreme character. Especially, this is confirmed under the conditions of the presence of clay minerals in the composition of n.d. Increasing the collector flow rate to 16 g/t does not give the desired beneficiation results, since the possible degree of extraction of clay impurities into the concentrate is at least 40%. The extremum in the recovery rate coincides with 8 g/t collector consumption. The range of the extremum of the degree of extraction of non-clay substances corresponds to the relatively high consumption of the collector (10 g/t). However, the degree of extraction of non-clay impurities into the concentrate is about 38% of the total content of n. about. An increase in temperature causes a noticeable displacement of the extremum of extraction of clay substances to higher values of the collector flow rate, and of non-clay substances, on the contrary, in the opposite direction of values along the horizontal axis.
Thus, in order to ensure the maximum recovery of insoluble impurities into the flotation sludge product, the determining factor is the choice of the optimal flocculant flow rate at the base flow rate of the sludge collector.
Research has been carried out on the flotation of water-insoluble impurities and potassium chloride, aimed at increasing the efficiency and selectivity of desliming potash ores and reducing the loss of potassium chloride during flotation processing of potash ores.
References / Список литературы
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3. Lyubimenko V.A., MityukD.Yu., Frolov V.I., Vinokurov V.A. Workshop on the course «Physical and colloidal chemistry». Textbook. 3 rd ed., Rev., Rev. and additional. Moscow: FSUE "Oil and Gaz", Russian State University of Oil and Gas named after I.M. Gubkin, 2013. P. 125.
4. Neudachina L.K., Petrova Yu.S. Application of surfactants in analysis: [textbook manual] / Ministry of Education and Science Russian Federation. Ural. Feder. University, 2017. P. 76.
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