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Conclusion. Comparison with literature data demonstrate the feasibility ofprocessing described waste
revealed that the obtained target products for adsorption of the Republic of Uzbekistan on carbon adsorbents. activity are at the level of the activated carbon from Evaluated the prospect of processing the waste pits
stone raw materials, which is one of the highest quality of apricots and peaches are formed on the enterprises of
global industrial activated coals, and far superior to many food industry of the Republic of Uzbekistan on activated
other carbon adsorbents (table 5). Thus, the studies carbons.
References:
1. Large-scale controls on potential respiration and denitrification in riverine floodplains./ELSEVIER/Marth, 2012/73-84.
2. Attachment of faecal coliform and macro-invertebrate activity in the removal of faecal coliform in domestic wastewater treatment pond systems./ELSEVIER/Marth, 2012/35-41.
3. Kinle Kh., Bader E. Active carbons and their industrial application (translated from the German). - L.: Chemistry, 1984. - P. 215.
4. Butyrin G. M. Highly porous carbon materials. - M.: Chemistry, 1976. - P. 187.
5. Greg S., Singh N. Adsorption, specific surface, porosity. - M.: Mir, 1970. - P. 408.
6. Dubinin M. M., Radushkevich, L. V.//Rep. of AS of USSR, 1947. - V. 55. - P. 331.
7. Kolyshkin D. A., Mikhailov K. K. Active carbon. Properties and test methods. Directory. - L.: Chemistry, 1972. - 57 P.
8. Active coals. Elastic sorbents. Catalysts, dehydrators and chemical absorbers based on them. Item catalogue under the General editorship ofV. M. Mukhin. - M.: Ore and metals, 2003. - 280 p.
9. "Water treatment", No. 8/2010. ID "Panorama".
10. "Treatment" № 9/2010. ID "Panorama".
11. Anurova T. V. Development of technology of active carbons from vegetable waste and their use for the protection of air from vapors of hydrocarbons: dis. cand. tech. sc. - M., 2003. - P. 54-55. - P. 68-102.
12. Mukhin V. M., Zubova I. D., Zubova I. N., Solovyov S. N., Yakovlev E. N. Method of producing active coal//Patent of Russia № 2393990/13, 06.04.2009.
13. Baklanova O. N., Plaksin G. V., Lavrenov A. V., Knyazeva O. A., Likholobov V. A. Technology of production of porous carbon materials//Patent of Russia № 2451547, 31.08.2010.
Sobirov Mukhtorjon Mahammadjanovich, Junior scientific researcher Academy of Sciences Republic of Uzbekistan Institute of General and inorganic chemistry, Tashkent, Uzbekistan E-mail: fcb_m_2011@mail.ru Sultonov Bokhodir Elbekovich, PhD in technique, senior reseacher of laboratory of Phosphorous fertilizers, Academy of Sciences of the Republic of Uzbekistan, Institute of General
and inorganic chemistry, Tashkent, Uzbekistan E-mail: i_umbarov@mail.ru Tajiev Sayfuddin Muhitdinovich, PhD in chemistry, Head of laboratory of Complex fertilizers, Academy of Sciences Republic of Uzbekistan Institute of General and inorganic chemistry, Tashkent, Uzbekistan
E-mail: sayf49@rambler.ru
Suspended sulfur containing fertilizers based on low-grade Kyzyl-kum phosphorites
Abstract: In this article, the principal opportunities for intensive technology of complex suspended sulfur-containing fertilizers wide actions based on unconcentrated phosphorites from Central Kyzylkum
have been given. There has been found the chemical composition of the fertilizers and expansion coefficient of phosphorite flour. In order to obtain optimal ratios and an increase of nutrients in plant during vegetation periods, and improvement of rheological properties of the nitrogen-phosphate slurry, it was added that required amount of ammonium nitrate solution obtained by neutralization of nitric acid with gaseous ammonia.
Keywords: phosphorite flour, ground sulfur, nitric acid, ammonia, ammonium nitrate.
Introduction. In recent years, the global fertilizer ammonia, sulfur, and phosphate raw materials is quite
market has a high demand for various types of liquid and suspended NPK-fertilizers. Such a situation is caused, primarily, their high agrochemical value, as the fertilizer applied to the soil that allows simultaneously all three of the most valuable nutritional elements — nitrogen, phosphorus and potassium. Recently concentrated liquid complex mineral fertilizers have been replacing the traditional solid.
Among them are very perspective suspended complex fertilizer (SCF) [1; 2]. Suspensions of the complex fertilizer are saturated salt solutions, in which are dispersed fine crystals (particles) of insoluble salts, stabilizing agents and other substances. Concentrated suspended NPK-fertilizers, obtained using concentrated nitrogen fertilizers are the best with consumer point view. Ammonium nitrate and urea, in which the nitrogen content is 35.0% and 46.7% by weight respectively, are used as nitrogen containing components.
Phosphorite is the main industrial source of phosphorus is an important, necessary for the life cycle of all living organisms. However, the phosphorus's reserves in the soil are being depleted, so it is necessary to make this element in the form of natural or chemical fertilizers.
In Uzbekistan, the Central Kyzyl Kum phosphate is the main raw material for phosphate fertilizers [3]. One ways of processing high calcareous phosphate raw material is nitric acid decomposition. The use of nitric acid largely economically justified, as resulting nitric acid suspensions can be used calcium nitrate fertilizer. In this regard, the methods of processing raw phosphate in nitric acid solutions are the greatest interest.
Currently in our country there are practically no technology for complex preparations universal actions for root and for foliar feeding, which are effective fertilizers and insecticides, exterminating spider mites and other sucking plant pests, although the work [4] is devoted to the production of liquid complex fertilizers based on phosphate and nitric acid.
From the above should be noted that the development of complex suspended nitrogen, phosphorus, potassium, calcium, and sulfur containing fertilizers technology based on nitric acid, potassium chloride,
topical.
Objects and Methods. To obtain new types of complex fertilizers in laboratory experiments were used the following: unconcentrated phosphorite flour of Central Kyzylkum with composition (wt.%): P2O5-17.55; CaO - 43.68; CO2-14.83; MgO - 1,68; R2O3-2,47; S03-1.01; F - 2,17; H2O - 1.19; insoluble residue -3.80%; ground sulfur, corresponding to State standard [5]; gaseous ammonia and 58.50% nitric acid. Stoichio-metric norm of nitric acid calculated on the decomposition of phosphate and carbonate minerals of the phosphate rock to form monobasic calcium phosphate and calcium nitrate. The norm of nitric acid was varied in the range of 30-70% of stoichiometry.
The mixture of the phosphorite flour and elemental sulfur was prepared at a ratio of 9: 1 to obtain suspended complex fertilizers. This mixture was thoroughly mixed, then it was decomposed by the first portion of nitric acid. The rest of the nitric acid is neutralized with ammonia gas, 64.16% ammonium nitrate solution is formed.
Decomposition of sulfur-containing phosphorite flour with acid is easily feasible. Component interaction occurs within 15-30 minutes. Process temperature, depending on the norm of acid varies in the range of 30-45 oC. To improve the quality and properties of the compound suspended in the resulting sulfur-containing fertilizer nitrogen-phosphoric pulp with constant stirring, the estimated amount of 64.16% solution of ammonium nitrate was added.
The contents of all forms of P2O5 (total, acceptable, water-soluble) in the products obtained was determined by photo-calorimetric method as a yellow complex phosphorus-vanadium-molybdenum complex on CPC-3 (= 440 nm) [6; 7]. The nitrogen content was determined by the distillation of ammonia on Kjeldahl and chlorine-amine method in according to [8]. The content of sulphate sulfur defined using barium chloride gravimetric method [9]. Elemental sulfur was determined by subtracting the sulphate form of sulfur of the total elemental sulfur taken to obtain the sulfur containing phosphorite flour. Determination of the content of all forms of calcium was carried out by complexometric titration
volume Trilon B in the presence of calcein or chrome dark blue indicators [10]. Expansion coefficient was calculated according to the formula: Ke = (PP^pJP&oJ -100% , where - P2O
5accep.
is
acceptable form on 2% citric acid, P2O5total is total phosphorus content in the fertilizer samples.
Results and discussion. The complex suspended sulfur-containing nitrogen-phosphorus fertilizer (N: P2O5 = 1:1) obtained at 30% norm of nitric acid contains 8.69% of total nitrogen, of which 35.09 % is in ammonium and a rest in nitrate, 8 67% of P2Otal, of which 4.03 is in water-soluble form, 21.64% of CaOtal, of which 24.03% is in water-soluble forms of CaO and 5.50% of the added ground sulfur in a hydrophilic state, including 72,73% of elemental, and 27.27% of sulphate
Table 1. - The chemical composition of the
form (Table. 1). The fertilizer mainly consists of calcium nitrate — 10.98%, ammonium nitrate — 30.46% of mono- and dicalcium phosphate as well as activated form of phosphorite flour in amount of 34.68% and sulfur — 5.70%. The amount of nutrients NPCaS is 44.71%.
With increasing amounts of ammonium nitrate to 30.46% in the composition of the slurry, i. e. a change in the ratio N: P2O5 from 1:1 to 1:0.5 the expansion coefficient (Ke) of phosphorite flour is increased from 38.32 to 40.03%.
With the increase of the nitric acid norm from 40% and 70% the content of water soluble form of phosphorus and calcium are raised from 0.71% to 1.71% and from 6.79% to 11.28%, respectively. Expansion coefficient of phosphorite flour is increased from 49.30% to 79.55%.
suspended sulfur-containing fertilizers,%
N: P2 O5 N P2O5 CaO S H O Re.
total nit-te am-m total water total water total elem. S°4
When norm HN O3 30%
1:0.5 12.53 7.21 5.33 6.27 0.28 15.6 3.75 4.11 2.89 1.08 23.65 40.03
1:0.6 11.59 6.82 4.77 6.86 0.30 17.08 4.11 4.50 3.16 1.18 22.49 39.65
1:0.7 10.65 6.44 4.21 7.46 0.32 18.56 4.46 4.89 3.43 1.29 21.34 39.28
1:0.85 9.67 6.05 3.63 8.08 0.34 20.1 4.83 5.30 3.72 1.39 20.14 38.86
1:1 8.69 5.65 3.05 8.68 0.35 21.64 5.20 5.70 4.00 1.50 18.94 38.36
When norm HN O 40%
1:0.5 12.35 7.41 4.94 6.17 0.54 15.37 4.93 4.05 2.43 1.48 24.50 51.05
1:0.6 11.41 7.05 4.36 6.75 0.59 16.8 5.39 4.43 2.65 1.62 23.44 50.67
1:0.7 10.46 6.69 3.77 7.33 0.63 18.24 5.84 4.81 2.88 1.76 22.38 50.34
1:0.85 9.49 6.32 3.16 7.92 0.67 19.72 6.32 5.20 3.11 1.90 21.29 49.87
1:1 8.52 5.96 2.56 8.52 0.71 21.20 6.79 5.59 3.35 2.04 20.19 49.30
When norm HN O 50%
1:0.5 12.17 7.60 4.56 6.09 0.75 15.15 6.07 3.99 2.20 1.65 25,32 61,41
1:0.6 11.23 7.27 3.96 6.64 0.81 16.53 6.63 4.36 2.40 1.8 24,36 60,99
1:0.7 10.28 6.94 3.35 7.20 0.87 17.92 7.18 4.72 2.61 1.95 23.39 60.42
1:0.85 9.32 6.60 2.72 7.77 0.93 19.35 7.75 5.10 2.82 2.1 22.41 59.85
1:1 8.35 6.26 2.09 8.35 0.99 20.78 8.33 5.48 3.03 2.25 21.42 59.16
When norm HN O 60%
1:0.5 12.04 7.82 4.22 6.02 1.11 14.98 7.21 3.95 2.09 1.72 26.21 71.26
1:0.6 11.10 7.51 3.58 6.56 1.21 16.34 7.86 4.31 2.27 1.88 25.34 70.73
1:0.7 10.15 7.21 2.95 7.11 1.30 17.69 8.51 4.66 2.47 2.03 24.47 70.18
1:0.85 9.19 6.89 2.30 7.66 1.40 19.08 9.18 5.03 2.66 2.19 23.58 69.71
1:1 8.22 6.57 1.65 8.22 1.49 20.47 9.84 5.39 2.86 2.35 22.68 68.98
When norm HN iO3 70%
1:0.5 11.87 8.01 3.86 5.94 1.30 14.78 8.29 3.89 1.99 1.77 27.01 81.31
1:0.6 10.93 7.72 3.21 6.46 1.40 16.09 9.03 4.24 2.17 1.92 26.22 80.96
1:0.7 9.99 7.44 2.55 6.99 1.50 17.41 9.77 4.59 2.35 2.08 25.43 80.54
1:0.85 9.03 7.14 1.89 7.53 1.61 18.75 10.52 4.94 2.54 2.23 24.63 80.08
1:1 8.07 6.85 1.22 8.07 1.71 20.09 11.28 5.29 2.72 2.39 23.83 79.55
We have also studied the change of acceptable form phosphorus and calcium in the obtained suspension of
complex fertilizers (Fig. 1) depending on the norms of nitric acid and the ratio of nutrients.
Figurel. The change of acceptable form of P2 05 (a) and CaO (b)content on 2% citric acid depending on the norm of HNO3 and ratio of N: P2 O5
It is found that with increasing nitric acid standards acceptable phosphorus and calcium forms increased. For example, at a ratio of N: P2O5 from 1: 1 and a norm of 30% nitric acid, content of acceptable phosphorus and calcium is 3.33% and 7.68% and the acid norm 70% equal to 6.42 and 15.67%, i. e. increased 1.92 and 2.04 times, respectively.
Thus, the increase of nitric acid's norm promotes to raise acceptable forms of phosphorus and calcium. However, it should be increased unwisely the norm of acid from this point of view, in this case there is
norm of nitric acid is 50-60%. The most widespread N: P2O5 in the fertilizer complex for the main crops such as cereals, sugar beet, cotton, potatoes, vegetables, fodder root crops are the following: 1: 0.5; 1: 0.7; 1: 1 [11] and the ratios are optimal.
The suspended complex sulfur-containing fertilizer mainly consists of water-soluble salts -15.24% of calcium nitrate, ammonium nitrate — 17.41% of mono- and dicalcium phosphate as well as 34.68% of activated form of phosphorite flour and 5.70% of sulfur. The amount of nutrients NPCaS makes 44.71% (Table 2).
overspending acid. Therefore, we think that the optimal
Table 2. - Salt composition of complex suspended sulfur-containing fertilizers,%
N: P2 °5 NH NO, 4 3 Са (NO3)2 mono-, dicalcium phosphate Activated phosphorite CaSO, 4 H2 O
1 2 3 4 5 6 7
When norm HNQ, 30%
1:0.5 30.46 10.98 4.73 25.00 5.18 23.65
1:0.6 27.26 12.03 5.13 27.37 5.69 22.49
1:0.7 24.06 13.07 5.53 29.75 6.21 21.34
1:0.85 20.4 14.15 5.92 32.21 6.71 20.14
1:1 17.41 15.24 6.28 34.68 7.22 18.94
When norm HNO3 4 10%
1:0.5 28.25 14.43 5.89 21.11 6.88 24.50
1:0.6 24.90 15.78 6.39 23.08 7.56 23.44
1:0.7 21.55 17.12 6.90 25.05 8.20 22.38
1:0.85 18.09 18.52 7.39 27.08 8.88 21.29
1 2 3 4 5 6 7
1:1 14.63 19.91 7.86 29.12 9.52 20.19
When norm HNO, 50%
1:0.5 26.10 17.78 6.96 17.34 7.61 25.32
1:0.6 22.62 19.41 7.54 18.92 8.33 24.36
1:0.7 19.13 21.04 8.10 20.51 8.96 23.39
1:0.85 15.54 22.72 8.66 22.15 9.69 22.41
1:1 11.96 24.40 9.20 23.79 10.41 21.42
When norm HNO, 60%
1:0.5 24.10 21.10 7.92 13.72 7.90 26.21
1:0.6 20.47 23.01 8.56 14.96 8.67 25.34
1:0.7 16.85 24.92 9.21 16.20 9.31 24.47
1:0.85 13.14 26.88 9.85 17.47 10.07 23.58
1:1 9.42 28.83 10.50 18.74 10.75 22.68
When norm HNO, 70%
1:0.5 22.08 24.29 8.90 10.15 8.07 27.01
1:0.6 18.33 26.45 9.64 11.05 8.79 26.22
1:0.7 14.58 28.61 10.38 11.95 9.52 25.43
1:0.85 10.77 30.82 11.12 12.88 10.2 24.63
1:1 6.95 33.02 11.84 13.80 10.92 23.83
As it is seen from the tabulated data that with the change in the ratio of N: P2O5 salt composition of the complex suspended fertilizer varies considerably. For example, at a ratio of N: P2O5 = 1: 0.5, and 30% nitric acid norm, the suspended fertilizer composition is the following: 10.98% of calcium nitrate, 30.46% of ammonium nitrate, 4.63% of mono- and dicalcium phosphate, 25.00% in active form of phosphorite, and 4.11% of sulfur. By changing the ratio N: P2O5 from 1: 0.5 to 1: 1 in the same norm of nitric acid in the obtained complex suspended fertilizer, content of the main component is increased, except the ammonium nitrate.
For example, at a norm of 50% nitric acid with a change in the ratio N: P2O5 from 1: 0.5 to 1: 1, the content of calcium nitrate, mono- and dicalcium phosphate, phosphorite flour in an activated form and sulfur increased from 19.41 to 24.40, from 7.54 to 9.20, from 18.92 to 23.79 from 4.36 to 5.48%, respectively, but ammonium nitrate content decreased from 22.62 to 11.96%.
Physicochemical properties of liquid fertilizer: density, viscosity, and crystallization temperature are important as they determine the conditions of production, storage, transportation and introduction into the soil. Therefore, we studied the rheological properties of the suspended complex fertilizers. Studies have shown that with increase temperature, decrease viscosity and density
of the fertilizer suspension is observed. The crystallization temperature of the suspended fertilizer varied from -7 to 6.5 °C. The suspended fertilizer containing high concentrations of calcium nitrate, i. e. obtained at excess nitric acid norms has much high crystallization temperature. pH of suspended complex fertilizers depending on the norms and ratios of nutrients is varied in the range 4-6.
Conclusion. There have been shown the principal opportunities for intensive technology of complex suspended sulfur-containing fertilizers wide actions based on unconcentrated phosphorites from Central Kyzyl-kum, for root and for foliar feeding, which are effective fertilizer and have insecticidal properties, exterminating some agricultural plant pests (spider mites and sucking pests). In order to obtain optimal ratios and an increase of nutrients in plant during vegetation periods, and improvement of rheological properties of the nitrogen-phosphate slurry, it was added that required amount of ammonium nitrate solution obtained by neutralization of nitric acid with gaseous ammonia. Proposed suspended sulfur-containing compound fertilizer compared with standard solid fertilizers has the following advantages: insecticidal properties; simplicity of production technology; meets all the requirements set by agricultural production.
References:
1. Efimova L. P., Malakhov N. N. production of suspended fertilizer. Chemical Industry. 1981. No 2. P. 27-28.
2. Postnikov A. V., Efremov L. N. Suspended fertilizer is a new form. Chemictry in Agriculture. 1992. No 3. P. 28-32.
Regeneration of activated carbon used in adsorption purification of alkanolamines
3. Beglov B. M., Namazov S. S., Phosphorites Central Kyzylkum and processing. Tashkent, 2013. 460 p.
4. Radjabov R., the Tajiev S.M, Tukhtaev S. Suspended liquid complex fertilizer. Achievements and prospects of complex chemical processing of fuel and mineral resources of Uzbekistan: Coll. mat. Rep. scientific. tehn. Conf. 7-8 October 2008. Tashkent, 2008. v. 2 P. 161-163.
5. State standard 127.5-93 sulfur ground for agriculture. Specifications. - M: Standard publication, 1993. 10 p.
6. Methodical instructions perform tests extraction pulp and extraction phosphoric acid. JSC "Ammophos - Max-am", Almalyk, - 2010. 22 p.
7. State standard 20851.2.75. Methods for determination of phosphorus content. - Minsk: Standards Publishing House, 1983, 22 p.
8. State standard 30181.4-94 Methods for determination of total mass fraction of nitrogen in compound fertilizers and nitrate in ammonium and nitrate forms (Devarda method). Intergovernmental council for Standardization, Metrology and Certification. Minsk. 1996. 7 p.
9. Vinnik M., Erbanova L. N., Zaitsev P. M. Methods of analysis ofphosphate rock, phosphate and compound fertilizers, feed phosphates. - M.: Chemistry.1975. 218 p.
10. Handbook of chemicalization in agriculture/Ed. V. M. Borisova. - M.: Kolos, 1980, 500 p.
Khayitov Ruslan Rustamjonovich, Institute of General and Inorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan, doctoral student, the Laboratory of Chemistry of Oil
E-mail: leo-bexa@mail.ru Narmetova Gulnara Rozukulovna, Institute of General and Inorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan, Chief scientific officer, the Laboratory of Chemistry of Oil Shermatov Bobomirza Eshbaevich, Uzbek Scientific Research Chemical-Pharmaceutical Institute
named after A. Sultanov UzKFITI, Tashkent, Uzbekistan, head of the laboratory, E-mail: bobomirza@mail.ru
Regeneration of activated carbon used in adsorption purification of alkanolamines
Abstract: Studied the methods of regeneration of spent activated carbon. Regeneration of spent activated carbon was carried out in laboratory conditions by high temperature treatment of spent activated carbons in an environment of water vapor and nitrogen at 750±20 °C; 800±20 °C; 850±20 °C temperature regimes.
Keywords: activated carbon, regeneration, adsorption, desorption, reactivation, heat treatment, the specific area, adsorption activity.
Introduction. The adsorption process has wide application in environmental engineering for treating and cleaning gas industrial emissions and sewage. It allows you to quickly and effectively remove from any environmental toxicants. As adsorbents can be used various materials with a certain chemical composition, crystal structure, the mechanism of their action must conform to the following principles [1]:
- have a high adsorption activity directed action;
- do not change the natural balance of substances in all parts of the ecosystem;
- have the ability to regenerate;
- to be able to recycling.
On oil and gas companies to capture hydrocarbons of oil and oil products from waste water is used as a highly effective adsorbent activated carbon, which meets all the
