Chemical behavior of indigenous impurities (Al, Fe, Si, Mg, F, K, Na, NH{sub 3}, Ca, and SO{sub 4}) during the production of filter-grade wet-process phosphoric acid
The conventional (dihydrate process) extraction of phosphate rocks with sulfuric acid and subsequent filtration results in a dilute ``filter-grade`` wet-process phosphoric acid (WPA) containing many cationic and anionic impurities which can cause problems during fertilizer production. Most of these problems result because many of the impurities are present in amounts above saturation. This factorial study was designed to define the nature and amounts of components precipitating from simulated filter-grade (28% P{sub 2}O{sub 5}) phosphoric acid at 85, 68, and 25 C, with 2-day retention times. Results show that the precipitation of the iron ammonium and iron potassium phosphates generally provide the largest source of solids in filter-grade phosphoric acid; Mg and Ca fluoroaluminates and alkali fluorosilicates also provide a significant proportion of solids. The distribution of solids between these 3 groups is governed by the F/Si ratio in the acid. The study also delineates the deleterious effect of ammonia contamination (such as from ammonia leakage to gypsum ponds).
- Research Organization:
- National Fertilizer and Environmental Research Center, Muscle Shoals, AL (United States)
- Sponsoring Organization:
- Tennessee Valley Authority, Knoxville, TN (United States)
- OSTI ID:
- 10107752
- Report Number(s):
- TVA/NFERC-91/7; TVA-Bull-Y-220; ON: DE93003873
- Resource Relation:
- Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
Similar Records
Organic reagents for removing heavy metals from a 10-34-0 (N-P[sub 2]O[sub 5]--K[sub 2]O) grade fertilizer solution and wet-process phosphoric acid
Organic reagents for removing heavy metals from a 10-34-0 (N-P{sub 2}O{sub 5}--K{sub 2}O) grade fertilizer solution and wet-process phosphoric acid
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FERTILIZERS
CHEMICAL PREPARATION
PHOSPHORIC ACID
PRODUCTION
PHOSPHATE ROCKS
EXTRACTION
IMPURITIES
AMMONIA
CHEMISTRY
CHEMICAL COMPOSITION
REGRESSION ANALYSIS
SOLUTIONS
TEMPERATURE RANGE 0273-0400 K
PRECIPITATION
SALTS
553000
400201
AGRICULTURE AND FOOD TECHNOLOGY
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES