Influence of addition of calcium salts on extraction of potassium from phosphorus- potassium associated mineral

2021 ◽  
Vol 20 (2) ◽  
pp. 219-229
Author(s):  
Feng Gao ◽  
Tao Chen ◽  
Liang Li
Keyword(s):  
Sulfuric Acid ◽  
Hydrofluoric Acid ◽  
Reaction System ◽  
Potassium Feldspar ◽  
Water Soluble ◽  
Mineral Deposits ◽  
Calcium Salts ◽  
Factors Affecting ◽  
Soluble Phosphorus ◽  
Maximum Extraction

In this article, calcium salts were added into the hydrofluoric acid-sulfuric acid (HF-H2SO4) leaching system, and their effects on the extraction of potassium from phosphorus-potassium associated mineral (mineral deposits containing Ca5(PO4)3F (fluorapatite) and KAlSi3O8 (potassium feldspar)) were investigated. KAlSi3O8 was converted into water-soluble potassium fertilizers, and important factors affecting the extraction, including dosages of H2SO4, types and dosages of calcium salts were studied. The results showed that the maximum extraction of 75.3 wt.% was obtained with H2SO4 (70 wt.%) dosage of 5 mL. When the reaction was added with 0.15 g CaSO4, the extraction rate of K of 95 wt.% was achieved, which was an increase by 19.7 wt.% compared with that without calcium salts. Moreover, the Eh-pH diagrams for K-Si-(P)-(F)-(Ca)-H2O systems were plotted and applied to analyze the mechanism of potassium extraction in the HF-H2SO4 reaction system. The analysis demonstrated that with the presence of F-, the formation of fluoro-complexes enlarged the stable regions of soluble phosphorus (KPF6) and silicon (K2SiF6). However, when calcium salts were added, such region decreased with the increase of [Ca2 +]; and such trends suggested that [K+] could be enhanced by adding [Ca2 +] during the leaching process.

Study on Technology of Extracting Potassium with Alkaline Hydrothermal Method

2012 ◽  
Vol 512-515 ◽  
pp. 2325-2328
Author(s):  
Xin Zhi Wang ◽  
Wei Liu ◽  
Ming Chang ◽  
Shuang Jie Xu ◽  
Jian Guo Song
Keyword(s):  
Crystal Structure ◽  
Reaction Time ◽  
Reaction System ◽  
Potassium Feldspar ◽  
Experimental Result ◽  
Optimal Conditions ◽  
Hydrothermal Conditions ◽  
Factors Affecting ◽  
Xrd Phase Analysis ◽  
New Phase

In this thesis, potassium feldspar - NaOH reaction system under hydrothermal conditions was established. The aims of this research were to discuss comprehensively the factors affecting potassium dissolution rate of the system. The experimental result indicated: effect on the extracting rate of potassium, NaOH concentration > the reaction temperature > reaction time; The rate of extracting potassium can be up to 70% under the optimal conditions; XRD phase analysis of ore and slag filtering showed that NaOH additive destroyed the crystal structure of potassium feldspar, and formed a new phase.

Nitrogen enrichment of animal bone-derived biochars as an agricultural NP-fertilizer 

2021 ◽  
Author(s):  
Gerhard Soja ◽  
Dominik Tauber ◽  
Jan Höllrigl ◽  
Andrea Mayer ◽  
Christoph Pfeifer
Keyword(s):  
Phosphorus Content ◽  
Water Soluble ◽  
Meat Production ◽  
Colorimetric Determination ◽  
Animal Bone ◽  
Soluble Phosphorus ◽  
Sorption Potential ◽  
P Supply ◽  
Np Fertilizer

<p>Food processing creates many by-products, and not all of them are used efficiently. Especially animal-based side products are frequently considered as waste with costly disposal requirements. For recycling of the nutrients contained in these residues, also under consideration of the hygienic specifications, pyrolysis can be used to create animal bone-based biochars. A lab-scale pyrolysis reactor (Pyreka 3.0) was used to produce biochars from different bone fractions of cattle and pigs after these bones had originated as waste from abbatoir operations. This study had the objective to investigate the potential of the bone chars to serve as a phosphorus (P) supply for agricultural purposes and to study the ammonium sorption potential of these chars.</p><p>The total phosphorus content of bones reached up to 140 mg/g. The water-soluble phosphorus content was in the range of 0.16 – 0.93 mg/g, an increase in pyrolysis temperature from 350 °C to 500 °C or 650 °C increased the water-soluble content by 13.3 or 12.2 % respectively. The citric acid soluble phosphorus content was between 1.75 – 2.19 mg/g. After pyrolysis temperatures of 350 °C, slightly more phosphorus dissolved in the coal products than at 500 °C (+2.7 %) and at 650 °C (+5.5 %).</p><p>The ammonium sorption capacity of biochars produced by varying pyrolytic processes was investigated by a series of sorption experiments. The removal of ammonium by the biochars from an aqueous ammonium solution was measured by using colorimetric determination of the ammonium content. The maximum ammonium sorption results were achieved by biochars produced from bovine heads and feet respectively at a temperature of 900°C and activated with H<sub>2</sub>O.</p><p>When exposed to a solution containing 50 mg/L of ammonium, these biochars adsorbed 1.23 and 1.14 mg ammonium/g biochar, respectively. The possibility to enrich abattoir waste biochars, which are depleted in nitrogen because of the pyrolysis process, with ammonium gained from a nitrogen-enriched biogas slurry produced from animal residues of the meat production process was tested using a substitute slurry made with ammonium sulfate. The highest absorbance rate using the substitute slurry containing 10 g/L ammonium was achieved by biochar made from bovine heads and resulted in 43.1 mg ammonium/g biochar.</p><p>This study shows that bone-based biochars enriched with nitrogen from e.g. biogas digestates have significant potential as an NP-fertilizer that supports the strategies of circular economy.</p>

PHOSPHORUS AND POTASSIUM SUPPLY FOR ALFALFA IN SOILS SAMPLED AT DIFFERENT DEPTHS

1957 ◽  
Vol 37 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. L. Halstead ◽  
K. F. Nielsen ◽  
A. J. MacLean
Keyword(s):  
Total Phosphorus ◽  
Greenhouse Experiment ◽  
Water Soluble ◽  
Organic Form ◽  
Pronounced Difference ◽  
Soluble Phosphorus ◽  
Potassium Supply ◽  
Different Depths ◽  
Phosphorus And Potassium ◽  
Depth Water

Results of a greenhouse experiment, comprising soil samples taken at three depths from each of six locations in eastern Ontario, indicated that the phosphorus-supplying power of the surface was considerably greater than that of the corresponding subsurface samples of four of the soils. The relative amounts of total phosphorus in surface and subsurface samples varied with the soils, the most pronounced variation being an increase in a sandy soil with depth. The proportion of the total phosphorus found in organic form varied from 18 to 56 per cent in the surface and from 5 to 33 per cent in the subsurface samples. The amounts of acid-soluble phosphorus extracted from five of the soils increased with depth. The amounts of NaHCO3-soluble phosphorus were higher in the surface than in the subsurface samples of five of the soils. The values for acid-soluble phosphorus in five of the soils and for NaHC03-soluble phosphorus in three of the soils were not in agreement with greenhouse results.The data from the greenhouse experiment did not indicate a pronounced difference between the potassium-supplying powers of corresponding surface and subsurface samples. Exchangeable potassium did not vary appreciably between surface and subsurface samples of four of the soils but decreased in two of the soils with depth. Water-soluble potassium decreased with depth in most instances.

Sign in / Sign up

Export Citation Format

Share Document