Study of porous phospho-gypsum composites and their properties on the basis of nostochiometric interpolymer complexes

 
 

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SCIENCE AND INNOVATION 
INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 2 ISSUE 3 MARCH 2023 
UIF-2022: 8.2 | ISSN: 2181-3337 | SCIENTISTS.UZ 
45
Chemical analysis resultssamples of phosphogypsum of Ammophos-Maxam OJSC 
The name of indicators 
Phosphogypsum (stale), dump of Ammofos 
OJSC 
density g / cm3 - 2.3 
density g / cm3 -
2.4 
 
1. P2O5total 
2.00 
1.39 
2. SO3 
44.33 
44.95 
3. CaO 
29.81 
31.33 
4. Fe2O3 
0.29 
0.64 
5. Ftotal 
0.42 
0.39 
6. SiO2 
13.75 
12.44 
7. Al2O3, 
0.31 
0.58 
8. Fe2O3
0.29 
0.64 
9. MgO 
footprints 
0.5 
Insoluble residue 
9.09 
7.78 
According to technical characteristicsstale phosphogypsum, placed on the dump of the 
AmmofosMaxam mineral fertilizer plant, meets the requirements of TU 113-08-418-94 
"Phosphogypsum for agriculture" grade No. 2 and therefore can be used for chemical land 
reclamation. 
Forspecimens of stagnant phosphogypsum (wastes of Ammofos-Maxam OJSC) the 
specific effective activity of natural radionuclides was determined, on the basis of which the 
sanitary and epidemiological conclusion was given that phosphogypsum samples correspond to 
SP No. 202 of 03.02.2012. “Sanitary and epidemiological requirements for ensuring radiation 
safety” and phosphogypsum can be used in economic activities without restrictions. For 
phosphogypsum samples, toxicological parameters were determined, which showed that the 
toxicity value of the aqueous phosphogypsum filtrate in the experiment on laboratory animals 
(white mice) corresponds to the 4th hazard class. The total toxicity index of the phosphogypsum 
sample is 7.53 units, which according to GOST 30774-2001 classifies this waste as hazard class 5 
(non-hazardous). 
The total area of solonetzSoils in the Republic of Uzbekistan make up more than 2 million 
hectares, of which about 50% of the irrigated lands of Khorezm and the Republic of 
Karakalpakistan were subjected to salinization, salinization, and loss of nutrient reserves. For this 
reason, crop yields on these lands decreased by almost 2 times. 
To increase crop yieldson solonetzic and saline soils, it is necessary to increase calcium 
reserves in them by adding calcium-containing chemical ameliorants (gypsum, phosphogypsum). 
Under the conditions of the abovementioned viloyats, the most effective chemical reclamant is 
phosphogypsum, obtained as an industrial waste of phosphorus production. The Ammophos-
Maxam plant in Almalyk has accumulated a huge amount (over 60 million tons) of 
phosphogypsum, which consists mainly of calcium sulfate dihydrate (CaSO4 ∙ 2H2O), 
phosphogypsum also contains phosphates (1.3 - 2.9% ) [20,21] 
The main leaders in the production of phosphate raw materials and products made from it 
are the United States (43.97 million tons), China (29.0 million tons), Morocco (23.59 million tons) 

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