Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

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JournalDilmurod of Chemical Ergashev, Technology Mamura and Askarova, Metallurgy, Saidahral 51, 3, Tukhtaev2016, 287-296

INVESTIGATION OF THE MUTUAL INTERACTIONS OF THE COMPONENTS OF A SYSTEM SUBSTANTIATING THE PROCESS OF OBTAINING A NEW DEFOLIANT Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

Institute of General and Inorganic Chemistry Received 19 May 2015 Academy of Sciences of Uzbekistan Accepted 15 March 2016 Ulugbek street, 77-a, Tashkent, 100170 Republic of Uzbekistan E-mail: [email protected]

ABSTRACT

The heterogenic phase equilibria in the aqueous system composed of calcium chlorate, magnesium chlorate and carbamide were investigated. The solubility of the system was studied at 250С and 500С. It was found that the liquidus curve in the isothermal solubility diagram broke down into three branches corresponding to the crystallization of the initial components and the newly formed phase of (СlO3)2∙4CO(NH2)2·2H2O. The dependence of the physicochemical properties of the system on the composition was followed and the corresponding composition-properties diagram was constructed. Keywords: cotton defoliants, calcium chlorate, magnesium chlorate, carbamide.

INTRODUCTION cotton growing. A new calcium-magnesium chlorate defoliant is developed on the ground of the local raw ma- The early and rich crop of raw cotton of high tech- terial dolomite. The latter is decomposed by hydrochloric nological properties requires the timely defoliation by acid and subsequently treated with sodium chlorate [2]. chemical preparations called defoliants. The latter have It is known that a mixture of chlorate containing to be highly effective providing more than 80 % cotton preparations and mineral fertilizers increases the defo- phylloptosis in the course of a single treatment at low liating activity provided and decreases its deteriorating norms of consumption. Furthermore they are expected effect on the plants [3, 4]. To improve the defoliating to act mildly on the plants with no disastrous effect on activity of a new calcium-magnesium chlorate defoli- the crop, the seeds oil content and the lint cotton quality. ant by introducing carbamide to its composition it was The existing assortment of recommended defoliants does necessary to gain information on the mutual interactions not completely comply with the current demands of the of the initial components of the system: Ca(ClО3)2- agricultural and public health services. Мg(ClО3)2-Н2О, Са(ClO3)2-CO(NH2)2-Н2О and {40.03

But it is worth adding that chlorate containing de- % ∑[Ca(ClО3)2+Мg(ClО3)2] + 7.45 % ∑[CaCl2+MgCl2] foliants are not only cheap but low toxic as well. This + 52.52 % H2O}-CO(NH2)2. refers also to the defoliant widely used in Uzbekistan. It is a local product which contains 36 % of magnesium EXPERIMENTAL chlorate [1]. Magnesium chloride (bischofite) is used as a raw material for the production of magnesium chlorate The dihydrate calcium chlorate Ca(ClO3)2∙2H2O but 50 % of it is imported, which increases the defoliant’s required was obtained on the basis of the exchange reac- cost. That is why the increase of the chlorate contain- tion of fused calcium chloride with sodium chlorate in an ing preparations efficiency as well as the development acetone medium as described in ref. [5]. The exchange of new defoliants on their basis is an actual problem in reaction carried out resulted in obtaining of a calcium

287 Journal of Chemical Technology and Metallurgy, 51, 3, 2016 chlorate solution in acetone. The calcium chlorate isola- RESULTS AND DISCUSSION tion from the resulting mass was achieved by cooling upon acetone extract separation from the solid phase. The solubility of the components of the system of

The acetone was subsequently distilled under vacuum in Ca(ClО3)2-Мg(ClО3)2-Н2О is studied on the ground of the temperature range of 30°C - 35°C and then purified ten internal sections. Sections I-IV refer to the magne- by recrystallization. The magnesium chlorate used in the sium chlorate-water side going to calcium chlorate top, present study was synthesized by the method described while sections V-X refer to the calcium chlorate-water in ref. [6]. The carbamide used was of an analytical grade side going to magnesium chlorate pole. The solubility quality. It was subjected to a double recrystallization. polythermal diagram of Ca(ClO3)2-Mg(ClO3)2-H2O is Visual polythermal and isothermal methods of constructed based on the solubility data of the binary analyses were used in the study of the systems of interest systems and the internal section. It refers to temperature [7, 8]. The presence of chlorate and chloride ions was values ranging from the eutectic freezing point (-61.7°C) identified by volumetric permanganometric and argento- till 60.0°C (Fig. 1). metric methods [9, 10], that of calcium and magnesium The fields of crystallization of the solid phases of ice, ions was determined by atomic-absorption spectro- hexa-, tetra- and dihydrated calcium chlorates as well as photometry [11]. The content of nitrogen, carbon and sixteen-, twelve-, hexa- and tetra hydrated magnesium hydrogen was estimated in accordance with the proce- chlorates are demarcated on the polythermal solubility dure described in ref. [12]. The analytical data obtained diagram of the system studied. The fields converge in four was used to determine solid phase composition by the nodal points of the invariant ternary system (Table 1). Schreinemakers’ method [13]. The latter were addition- The isothermal curves of solubility are plotted at ally studied by various chemical and physico-chemical every 10°С in the polythermal diagram of state. The methods of analysis. The thermal analysis of the new projections of the polythermal curves of solubility are phase obtained was carried out on a Paulik-Paulik-Erdei constructed on the water side of the system studied. It derivatograph. X-ray diffraction analysis was performed is seen that new chemical compounds are not formed. on DRON-3.0. Interplanar spacings values were found The system behaves as a simple eutonical one. in a reference book [14] on the ground of the angle of reflection, whereas the intensity of the diffraction lines was evaluated using the hundred points scale. The mutual interaction of the components in the system Ca(ClO3)2-Mg(ClO3)2-H2O was studied by a visual polythermal method in a wide temperature and concentration range. The calcium chlorate-water and magnesium chlorate-water binary systems were previ- ously studied. The data obtained is in agreement with that in the literature [15, 16]. The TG and DSC measurements were carried out with a Netsch Simultaneous Analyzer STA 409 PG equipped with aluminum crucibles and a TG/DSC sample carrier supporting a type K (Low RG Silver) thermocouple. All experiments were carried out in a nitrogen atmosphere with N2 flow rate of 50 ml min-1. The temperature ranged from 20oC to 550oC, while the heating rate was 10oC min-1. The sample mass was 8.5 mg. The measuring system was calibrated using standard compounds: diphenyl ether, indium, tin, potassium nitrate and potassium perchlorate. All temperatures values reported are the so-called extrapolated onset Fig. 1. Solubility diagram of Ca(ClO3)2-Mg(ClO3)2-H2O temperatures if not otherwise stated. system. 288 Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

Table 1. Double and triple nodal points of Ca(ClO3)2-Mg(ClO3)2-H2O system. Composition of the liquid phase, % t , Solid phase Ca(ClO ) Mg(ClO ) Н О crys 3 2 3 2 2 ºС - 36.9 63.1 -52,0 Ice+Mg(ClO3)2·16Н2О

6.4 35.3 58.7 -61.7 Ice+Ca(ClO3)2·6Н2О+Mg(ClO3)2·16Н2О

9.3 27.3 63.4 -55.2 Ice+Ca(ClO3)2·6Н2О 16.4 18.3 65.3 -48.4 Same 18.6 16.7 64.7 -47.7 -//- 26.5 11.6 61.9 -44.2 -//- 36.6 6.4 57.0 -42.2 -//- 37.8 5.7 56.5 -41.7 -//- 46.1 - 53.8 -40.3 -//- - 42.0 58.0 -21.7 Mg(ClO3)2·16Н2О+Mg(ClO3)2·12Н2О Mg(ClO ) ·16Н О+Mg(ClO ) ·12Н О+ 4.8 41.0 54.2 -35.0 3 2 2 3 2 2 Ca(ClO3)2·6Н2О

5.0 38.0 57.0 -41.8 Mg(ClO3)2·16Н2О+Ca(ClO3)2·6Н2О

- 45.4 54.6 -7.5 Mg(ClO3)2·16Н2О+Ca(ClO3)2·6Н2О Mg(ClO ) ·12Н О+Mg(ClO ) ·6Н О+ 3.9 45.0 51.1 -15.6 3 2 2 3 2 2 Ca(ClO3)2·6Н2О 55.0 - 45.0 -27.2 Ca(ClO3)2·4Н2О+Ca(ClO3)2·6Н2О 50.5 5.0 44.5 -27.4 Same 44.0 11.8 44.2 -27.8 -//- 36.4 19.7 43.9 -28.0 -//- 27.5 29.8 42.7 -28.2 -//- 14.6 52.0 33.4 -29.4 -//- 62.0 - 38.0 -6.8 Ca(ClO3)2·2Н2О+Ca(ClO3)2·4Н2О 57.5 4.7 37.8 -7.0 Same 52.0 10.2 37.8 -7.3 - // - 46.2 16.7 37.1 -7.6 -//- 44.0 19.4 36.6 -7.9 -//- 39.8 24.8 35.4 -8.1 -//- 28.3 43.0 28.7 -8.9 -//- - 63.3 36.7 34.2 Mg(ClO3)2·6Н2О+Mg(ClO3)2·4Н2О Mg(ClO ) ·6Н О+Mg(ClO ) ·4Н О+ 3.2 62.8 34.4 30.0 3 2 2 3 2 2 Ca(ClO3)2·6Н2О

The analysis of the solubility polythermal diagrams Thus, the study of the interactions of the compo- of Ca(ClO3)2-Mg(ClO3)2-H2O indicates that the com- nents in Ca(ClO3)2-Mg(ClO3)2-H2O system shows that ponents of the system exert mutual salting-out effects. the components exert mutual salting-out effects but no Magnesium chlorate provides a greater salting-out ef- new compounds are formed. fect than calcium chlorate due to its good solubility and The effect of the joint presence of calcium chlorate hence, the field of calcium chlorate crystallization ex- and carbamide is studied by the isothermal method at pands with magnesium chlorate concentration increase. 25°C and 50°C. The equilibrium phases are obtained at Thus, in presence of 50 % of magnesium chlorate, the both temperature values under continuous stirring and solubility of calcium chlorate decreases at 10°C, 20°C, temperature control in every 2.5 – 3 days and 1.5 - 2 30°C, 40°C and 50°C and amounts to 38.2 %, 38.4 days, respectively.

%, 38.0 %, 38.2 % and 38.3 %, correspondingly. The The investigation of Ca(ClO3)2-CO(NH2)2-H2O comparison is carried out on the ground of the initial system is carried out along the calcium chlorate side, solubility of calcium chlorate in pure water. whose solubility in water at the temperatures studied

289 Journal of Chemical Technology and Metallurgy, 51, 3, 2016

Table 2. Solubility data of Ca(ClO3)2-CO(NH2)2-H2O system at 25°С. Content of the liquid Content of the “solid № phase, mass % residue”, mass % Solid phase Cа(ClO3)2 CO(NH2)2 Ca(ClO3)2 CO(NH2)2

1 - 55.0 0.4 95.0 CO(NH2)2 2 4.0 55.2 0.5 96.0 Same 3 8.7 55.4 1.1 95.4 -//- 4 14.0 56.0 1.5 94.9 -//- 5 22.4 57.2 27.2 68.9 CO(NH2)2+Ca(ClO3)2∙4CO(NH2)2∙2H2O 6 21.0 51.0 40.4 50.0 Ca(ClO3)2∙4CO(NH2)2∙2H2O 7 21.8 44.3 40.7 49.2 Same 8 22.2 40.5 40.2 48.4 -//- 9 23.8 34.8 41.0 48.0 -//- 10 25.7 28.2 40.9 47.2 -//- 11 29.2 23.7 41.8 47.3 -//- 12 33.4 19.8 42.0 46.4 -//- 13 38.3 15.9 42.4 46.0 -//- 14 43.4 12.2 43.2 45.9 -//- 15 48.3 9.5 43.8 45.2 -//- 16 54.8 6.2 44.0 45.8 -//- Ca(ClO ) ∙4CO(NH ) ∙2H O+ 17 59.7 3.7 72.8 22.9 3 2 2 2 2 Ca(ClO3)2∙2H2O 18 62.9 1.8 81.0 0.4 Ca(ClO3)2∙2H2O 19 66.4 - 85.2 - Ca(ClO3)2∙2H2O are 66.4 % and 73.5 %, correspondingly. The solubil- that the liquidus curve is divided into three branches, cor- ity isothermal diagrams of the system (Figs. 2 and 3) responding to the crystallization of the two initial com- are constructed at 25°C and 50°C on the ground of the ponents (CO(NH2)2 and Ca(ClO3)2∙2H2O) and the newly chemical analysis of the components of the liquid and formed compound of Ca(ClO3)2∙4CO(NH2)2∙2H2O. The solid phases (Tables 2 and 3). crystallization branch of the latter has a relatively large area.

The solubility isothermal diagram of the system shows The concentration limits of Ca(ClO3)2∙4CO(NH2)2∙2H2O

Fig. 2. Solubility isotherm of Ca(ClO ) -CO(NH ) -H O 3 2 2 2 2 Fig. 3. Solubility isotherm of Ca(ClO3)2-CO(NH2)2-H2O system at 25°С. system at 50°С. 290 Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

Table 3. Solubility data of Ca(ClO3)2-CO(NH2)2-H2O system at 50°С. Content of the Content of the liquid phase “solid residue” № mass % mass % Solid phase

Cа(ClO3)2 CO(NH2)2 Ca(ClO3)2 CO(NH2)2

1 - 67.1 0.5 95.7 CO(NH2)2 2 5.2 66.0 0.8 94.8 Same 3 10.0 65.8 1.7 94.5 -//- 4 14.9 65.6 2.6 94.3 -//-

5 20.5 65.4 3.1 94.8 CO(NH2)2+Ca(ClO3)2∙4CO(NH2)2∙2H2O

6 20.7 65.2 24.8 71.7 CO(NH2)2+Ca(ClO3)2∙4CO(NH2)2∙2H2O

7 20.9 65.1 41.2 50.8 CO(NH2)2+Ca(ClO3)2∙4CO(NH2)2∙2H2O

8 21.3 57.2 40.7 50.3 Ca(ClO3)2∙4CO(NH2)2∙2H2O 9 22.5 49.6 40.5 49.6 Same 10 24.7 43.8 40.9 48.9 -//- 11 27.8 37.5 41.3 48.6 -//- 12 31.9 32.4 42.0 48.2 -//- 13 37.8 26.8 42.2 47.4 -//- 14 43.9 21.9 43.1 46.4 -//- 15 52.1 19.9 44.0 46.1 -//- 16 57.8 20.3 44.6 46.5 -//-

Ca(ClO3)2∙4CO(NH2)2∙2H2O+ 17 64.8 22.4 45.3 46.3 Ca(ClO3)2∙2H2O

Ca(ClO3)2∙4CO(NH2)2∙2H2O+ 18 65.0 22.3 69.2 26.8 Ca(ClO3)2∙2H2O

Ca(ClO3)2∙4CO(NH2)2∙2H2O+ 19 65.2 22.1 82.8 3.1 Ca(ClO3)2∙2H2O

20 64.2 15.9 82.6 2.2 Ca(ClO3)2∙2H2O 21 64.4 10.8 82.9 1.5 Same 22 66.7 5.7 83.2 0.7 -//- 23 73.5 - 85.2 - -//- presence at 25°C refer to 3.7 % - 57.2 % of carbamide The comparison of the solubility isotherms of and 22.2 % - 59.7 % of calcium chlorate. The limits of Ca(ClO3)2-CO(NH2)2-H2O system at 25°С and 50°С the compound presence at 50°C correspond to 22.1 % shows that the dimensions of the branches referring to - 65.4 % of carbamide and 20.5 % - 65.2 % of calcium the initial components and the newly formed compound chlorate. The isolated Ca(ClO3)2∙4CO(NH2)2∙2H2O com- change with temperature increase from 25°C to 50°C. pound is characterized by the intersection of the straight Thus, the crystallization branches of calcium chlorate beams at a single point inside the triangle, which is an and the compound obtained in the isotherm at 50°C are indication of a hydrated compound formation. The significantly increased compared to those in the isotherm further analysis of the solubility diagram shows that the at 25°C. This is due to the fact that their solubility in- compound considered is congruently soluble in water. creases with temperature increase.

291 Journal of Chemical Technology and Metallurgy, 51, 3, 2016

Fig. 4. X-ray pattern of Ca(CIO3)2·4CO(NH2)2·2H2O (1) and Ca(CIO3)2·2H2O (2). The new phase formed in the system is isolated in a reflexes are different, both on the ground of the value crystalline form and identified by chemical, X-ray and of the interplanar distances and on the intensity of the thermal analyses. The chemical analysis shows that the diffraction lines (Fig. 4). mass of Ca(ClO3)2 is equal to 42.8 %, that of CO(NH2)2 Endo- and exo-thermal effects of melting and de- is equal to 49.73 %, whereas that of H2O is equal to 7.5 composition are outlined on the heating curves of the

%. The data referring to Ca(ClO3)2∙4CO(NH2)2∙2H2O compound. The endo-effect at 157°C (Fig. 5) refers to compound is as follows: the mass of Ca(ClO3)2 is equal its melting. Its decomposition proceeds at 292°C. The to 42.85 %, that of CO(NH2)2 is equal to 49.69 %, weight loss determined on the ground of the TG curve whereas that of H2O is equal to 7.45 %. refers to 77.2 %. The X-ray analysis of the initial components and Thus, a new compound of the composition of the newly formed compound shows that the diffraction Ca(ClO3)2∙4CO(NH2)2∙2H2O is obtained as a new phase

Fig. 5. A derivatogram of Ca(ClO3)2·4CO(NH2)2·2H2O (1); Ca(ClO3)2·2H2O (2). 292 Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

in the system of Ca(ClO3)2-CO(NH2)2-H2O at 25ºC and of the system studied. The data obtained provides the 50ºC,. construction of the solutions structure-property diagram The further aim of the study refers to the study (Table 4, Fig. 6). The composition vs. the system crys- of the process of obtaining a new and more effective tallization temperature is characterized by the presence preparation having a high defoliating activity and “soft” of two branches of crystallization with a clear break in action on cotton on the ground of calcium chlorate, the solubility curve according to the data chart (Fig. 6, magnesium chlorate and carbamide. This requires the Curve 1). Crystallization of {[84.3 % ∑Ca(ClО3)2+ identification of the physical and chemical properties of Мg(ClО3)2] + [15.69 % ∑CaCl2+MgCl2]} extends the solutions of {[40.03 % ∑Ca(ClО3)2+Мg(ClО3)2] + at -4.3°C to 14.55 % of carbamide. At this point, the

7.45%∑[CaCl2+MgCl2] + 52.52 %H2O}-CO(NH2)2. The crystallization of {[84.3 % ∑Ca(ClО3)2+Мg(ClО3)2] dependence of the crystallization temperature change, + [15.69 % ∑CaCl2+MgCl2]} and the compound of Ca pH, the refractive index, the viscosity and the density (ClО3)2·Мg(ClО3)2∙8СО(NH2)2·4H2O take place. The of solutions of various compositions are determined increase of the carbamide concentration by more than to ascertain the effect of the individual components 14.55 % causes crystallization of the compound of Ca

Fig. 6. Composition–property diagram of the system

{[40.03 % ∑Ca(ClО3)2+Мg(ClО3)2] + 7.45 % ∑[CaCl2+MgCl2] + 52.52 % H2O}-CO(NH2)2:

1-crystallization temperature; 2- рН; 3-refractive index (nD20); 4-viscosity; 5-density.

293 Journal of Chemical Technology and Metallurgy, 51, 3, 2016

Table 4. Composition dependence of the solutions crystallization temperature change, refractive index

(nD20), pH, viscosity, density in case of {[40.03 % ∑Ca(ClО3)2+Мg(ClО3)2] +7.45 % ∑[CaCl2+MgCl2]

+ 52.52 % H2O}-CO(NH2)2. № Content of components, % {[40.03%∑Ca(ClО3)2 t , η, crys d, g/cm3 рН n +Мg(ClО3)2]+ ºС mm2/s D20 7.45%∑[CaCl2+MgCl2] CO(NH2)2 +52.52%H2O} 1 100 - 10 6.69 1.5110 4.01 1.4300 2 98.86 1.14 9.4 6.83 1.5095 4.17 1.4320 3 97.1 2.90 8.2 7.08 1.5060 4.25 1.4337 4 95.8 4.20 7.0 7.25 1.5020 4.30 1.4350 5 93.66 6.34 5.2 7.45 1.4950 4.32 1.4366 6 91.5 8.50 3.0 7.89 1.4875 4.37 1.4383 7 90.0 10.0 1.4 8.14 1.4830 4.45 1.4393 8 88.66 11.34 -0.2 8.29 1.4800 4.50 1.4401 9 86.8 13.20 -2.4 8.56 1.4750 4.60 1.4412 10 85.45 14.55 -4.3 8.75 1.4715 4.71 1.4419 11 84.43 15.57 13.5 9.20 1.4635 4.94 1.4430 12 82.85 17.15 22.7 9.50 1.4590 5.12 1.4435 13 81.43 18.57 28.0 9.75 1.4550 5.30 1.4440

2 2 (ClО3)2·Мg(ClО3)2∙8СО(NH2)2·4H2O. The analysis of 6.69 mm /s to reach a value of 8.75 mm /s at the double the composition vs. pH dependence (Fig. 6, curve 2) point, i.e. in case of 14.55 %-content of carbamide (Fig. shows that pH of the solutions gradually increases by 6, curve 4). The viscosity of the newly formed solutions addition of carbamide. At the double point the solution increases with increase of the carbamide concentration pH value is equal to 4.71. It increases sharply from 4.71 and reaches a value of 9.75 mm2/s. This is determined to 5.30 on further increase of carbamide concentration. by a change in the field of the system crystallization. The composition–property diagram is also charac- The analysis of the composition vs. density graph terized by the presence of two branches of crystalliza- of the system (Fig. 6, curve 5) shows that the density of tion, with a fracture index (Fig. 6, curve 3). The viscosity the newly formed solutions decreases with increase of values of the solutions studied increase gradually from the carbamide concentration. There is also a fracture of

Fig. 7. X-ray diffraction spectrum of [Са(ClO3)2∙Mg(ClO3)2∙8CO(NH2)2∙4H2O]. 294 Dilmurod Ergashev, Mamura Askarova, Saidahral Tukhtaev

Fig. 8. TG-DSC of [Са(ClO3)2∙Mg(ClO3)2∙8CO(NH2)2∙4H2O]. curve 5 of the composition-property diagram. The crys- of 20°C - 50°C (Fig. 8). tallization branches of calcium and magnesium chlorates The isolated compound of the Са(ClO3)2∙Mg(ClO3) on one hand and calcium and magnesium chlorides on 2∙8CO(NH2)2·4Н2О is a white crystalline substance. Its the other correspond to solution densities of 1.5110 g/ solubility in water at 0°C, 10°C and 20°C is 54.4 mass cm3 - 1.4715 g/cm3 (Table 4). %, 59.0 mass %, and 62.8 mass %, respectively. The Тhe solutions density values of 1.4715 g/cm3 - compound is slightly soluble in an alcohol and acetic 1.4550 g/cm3 correspond to the crystallization branch acid, and hardly soluble in acetone and benzene. of Ca(ClO3)2·Mg(ClO3)2∙8CO(NH2)2·4H2O. It is necessary to dissolve carbamide in the solution

The formation of the compound Ca(ClО3)2·Мg(Cl of calcium-magnesium chlorate defoliant in a mass ratio

О3)2∙8СО(NH2)2·4H2O is verified by X-ray diffraction of 1.0:0.1 to obtain an effective “soft” acting preparation data. The comparison of the diffraction lines and the having defoliating activity. The latter is suggested on the corresponding values of the interplanar spacings of all ground of the composition-property study of the system species present show, that an individual compound of a mentioned above and the conducted agrochemical tests crystal lattice shown in (Fig. 7) is formed. of the defoliant components. Thus a defoliant solution

The TG-DSC investigation of Ca(ClО3)2·Мg(ClО3) of a temperature of crystallization of 1.4°C, viscosity 2 3 2∙8СО(NH2)2·4H2O carried out in the temperature range of 8.14 mm /s, density of 1.4830 g/cm , and pH of 4.45 from 20°C to 550°C is characterized by the presence of is obtained. an endothermal effect at 144.1°C and two exothermal one at 248.0°C and 264.7°C. The endothermal effect CONCLUSIONS at 144.1°C corresponds to water removal with corresponding weight loss of 7.86 % as evident from the The mutual interactions of the components of the sys-

TG curve. The exo-effect at 248.0°C corresponds to tems Са(ClO3)2-Mg(ClO3)2-Н2О; Са(ClO3)2-CO(NH2)2- the decomposition of the compound, while the weight Н2О and {[40.03 % ∑Ca(ClО3)2+Мg(ClО3)2] + 7.45 loss is 39.70 %. There is another exothermal effect at % ∑[CaCl2+MgCl2] + 52.52 % H2O}-CO(NH2)2 were 264.7°C. It is connected with further decomposition of studied at 25°С and 50°С. The results obtained showed the compound accompanied by weight loss of 76.13 %. that a new compound of a good defoliating activity was The total weight loss is 90 % in the temperature range obtained.

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REFERENCES 7. A.S. Trunin, D.G. Petrova, Visually polythermal method. Kuibyshev Polytechnic. Inst./: - Kuibyshev, 1. List of chemical and biological pest control, plant 1977. – p. 94. / Dep. in VINITI №584-78, (in diseases and weeds, defoliants and plant growth regu- Russian). lators permitted for use in agriculture of the Republic 8. A.G. Bergman, N.P. Luzhnaya. Physicochemical of Uzbekistan for 2002-2006, Tashkent, 2002, p. 96, basis of investigation and use of salty deposits of (in Russian). chloride-sulfate type. - Moscow: USSR Academy of 2. Z.A. Hamrakulov, M.K. Askarova, S. Tukhtaev, Sciences, 1951, p. 232. Preparation of calcium-magnesium chlorate defoliant 9. State standard 12257-77, Sodium chlorate, Moscow, from dolomite, Journal of Chemical Technology and Standard agency`s publishing house, 1987, p. 19, (in Metallurgy, 50, 1, 2015, 65-70. Russian). 3. S. Tukhtaev, Kh. Kucharov, A.Kh. Yusupov, 10. E.N. Dorokhova, G.V. Prokhorova, Analytical Synthesis of defoliant on the basis of calcium chemistry: Physical-chemical methods of analysis, chlorate-chloride and carbamide. XIV All-Union Moscow, 1991, (in Russian). Scientific and Technical Conference on Technology 11. I. Khavezov, D. Salev, Atomic Absorption Analysis, of inorganic substances and fertilizers, Abstracts, Part Sofia, 1980, (in Bulgarian). III. Lvov, 1988, p.50, (in Russian). 12. V.A. Klimova. Basic micro methods of analysis of 4. M.N. Nabiyev, S. Tukhtaev, R.E. Shammasov, N.Y. organic compounds. Moscow, Chemistry, 1975, p. Musayev, Sh. Burhanov, Investigation of phys- 224 (in Russian). icochemical properties of defoliants on the basis of 13. V.Y. Anosov, Descriptive geometry in application magnesium chlorate and components of fertilizers to chemical diagrams of the ternary and quaternary (such as UDM), Uzb. Chemical. J., 3, 1980, 48-51, systems, Moscow-Leningrad: Publishing House of (in Russian). the USSR Academy of Sciences, 1949, p.176, (in 5. A.S. 1143691 USSR. A method for producing cal- Russian). cium chlorate-chloride defoliant, M.N. Nabiyev, 14. Y.L. Giller, Tables of interplanar spacings, v.2. , M., R. Shammasov, S. Tukhtaev, Kh. Kucharov et al. Nedra, 1966, p. 330. (USSR) – No 3620951/23-26; reported on 23.05.83.; 15. A.N. Kirgintsev et al., The solubility of inorganic published on 07.03.85 // Discovery, invention. 1985, substances in the water, Leningrad, Chemistry, 1972, No 9, p. 84, (in Russian). p. 248, (in Russian). 6. Y.M. Martynov, M.A. Matveev, L.M. Yakimenko, 16. S. Tukhtaev, R.E. Shammasov, Kh. Kucharov, A.A. Furman, The technology of production and ap- Solubility polyterm of magnesium chlorate - water plication of magnesium chlorate defoliants, Chemical system, Dokl. AN Uz SSR, 1984, 1, 31-32, (in industry, 7, 1958, 420-423, (in Russian). Russian).

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