Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Phosphogypsum


The Solubility of Phosphogypsum and Recovery of Heavy and Radioactive Elements

Waleed T. Rashid; Israa A. Alkadir; Moayyed G. Jalhom

Engineering and Technology Journal, 2020, Volume 38, Issue 10A, Pages 1470-1480
DOI: 10.30684/etj.v38i10A.907

The essential purpose of this paper is to illustrate and inspect the leaching characteristics of Iraqi Phosphogypsum (PG). The paper presents the results of the dissolution characteristics of heavy and radioactive elements from PG, which is a by-product result from the industry of phosphate fertilizers. Leachability of heavy and radioactive elements in deionized water that has been inspected under various states of leaching, including solid/liquid ratio (10, 20 and 50 /1g/L) and temperatures (25, 45 and 85 °C), with constant other parameters such as string speed (300 rpm) and contact time (60 minutes). For the most analysis elements, the progressive release of the metals, in addition to the major elements reflects high mobility. The mobility of trace metals in PG has been generally classified into three main degrees: (1) high mobility elements such as Pb, Zn, Mn, and Cr; (2) moderate mobility elements such as Sr, V, Ba,Y,Hg, K and Ni; and (3)l ow mobility elements like Ca,Cu,Fe, and Ag. The maximum concentrations of the most of the metals were attained from a leaching state of 10/1g/L. Regarding temperature, the experimental results revealed that the PG solubility to leaching out elements increases noticeably as the applied temperature ranges from 25 to 45 °C; after this degree, the leaching efficiency decreases. Chloride had a positive and negative effect on the solubility of phosphorus. Calcium chloride had an adverse effect on solubility and observed reduced solubility with increased chloride. While the positive effect of sodium and magnesium chloride was observed, the solubility ratio increased with the increase of chlorides. However, the effect of magnesium chloride was higher compared to the sodium chloride one

Study on The Production of Ammonium Sulfate Fertlizer From Phosphogypsum

Khalid K. Abbas

Engineering and Technology Journal, 2011, Volume 29, Issue 4, Pages 814-821

The production of ammonium sulfate fertilizer from phosphogypsum
is studied. The phosphogypsum is considered by product from extraction process
of sulphoric acid. The mereseberg process is used a waste of phosphogypsum with
ammonium carbonate to produce ammonium sulfate as a main product and
calcium carbonate as a byproduct. It is a process could be used as a successful
method in phosphate industry (AL-Qauim).The flow diagram is drawn to illustrate
the mersberg process then material balance is done. The carbonation process is
one of the stage of mereseberg method, then carried out at constant temperature
(44Co) because of the reaction is exothermic and high temperature causes
decomposition of ammonium carbonate and low temperature causes precipitate
different kind of salts. From results of laboratory experiments the temperature of
ammonium sulfate preparation is done in 23Co and the ratio of phosphogypsum to
ammonium carbonate (400ml /192 gm phosphogypsum ) at reaction time( 4 )
hours. The aim of this work focus on making a process flow diagram which is
used in dealing with waste of phosphogypsum and production a useful product.