Monazite is a major source for REE and a secondary source for phosphate, thorium and uranium. Phosphate mine tailings, uranium and rare earth mine tailings contain radioactive thorium. For the most part this radioactivity is from the first decay product of thorium-232, which is radium-228, and from the decay sequence starting with radium-228.

Xenotime, a phosphate ore, is one of the valuable mineral deposits of rare earths similar to monazite.The main characteristics of xenotime are listed below: (1) The content of yttrium is high while that of the light rare earths is low (Table 12). (2) The content of thorium is lower than that in monazite (Table 13). (3) The composition of tungsten-containing …

Solvent extraction is a powerful separation technique in the preparation of nuclear grade thorium. In this study, monazite thorium concentrates produced from Malaysian monazite were used.

Separation and purification of thorium from monazite leach liquors was investigated by counter current extraction process. The Primene JM-T (mixture of highly branched C16 to C22 tertiary alkyl ...

Gravity and running water aid in the separation of hard grains of monazite and other heavy minerals from lighter minerals. They collect behind boulders, on the inside bends of stream channels, and eventually work their way down into the sediment deposit's lower levels. ... Monazite's thorium content varies, but it can reach 20–30% in some ...

The present work succeeded to develop new optional procedures to enhance the separation process of thorium and REEs. Selective precipitation of thorium with pyrophosphate was successfully attained for the upscale level in which, complete and efficient thorium separation (99%) was achieved with relatively low co-precipitation of …

An ion-exchange method has been developed for the separation of thorium from these elements. The method has also been applied to the determination of thorium and rare earths in monazite concentrates. (auth) ... >A process is described for the recovery of uranium and thorium from monazite sand, which is frequently processed by treating it …

Separation processes for RE solvent extraction from aqueous solutions have been reviewed. • Bastnesite, monazite, and xenotime are main sources of RE hydrometallurgical processing. ... During the 1960s, Thorium Limited in the United Kingdom used TBP to separate light rare earths in nitrate media (Sherrington, 1966). This process …

The amine extraction (Amex) process can be used effectively for the extraction and separation of thorium from monazite liquor in which rare earths coexist about 10 times richer than thorium. The results of batch tests on extraction of thorium with 0.18M Primene JM-T as a solvent show that nuclear grade thorium can be produced by a proper choice ...

Systematic studies were carried out to leach out rare earths and recover thorium from Korean monazite. Monazite was processed with acid baking process …

A process is described for recovering thorium, uranium, and rare earth values from monazite sand. The monazite sand is first digested with sulfuric acid and the resulting "monazite sulfate" solution is adjusted to a pH of between 0.4 and 3.0, and oxalate anions are added causing precipitation of the thorium and the rare earths as the oxalates.

A practical method for the separation and amperometric determination of thorium in monazite sands is proposed. The attack is carried out with sulfuric acid on 10-gram samples; thorium and the rare earths are separated by a single precipitation with oxalic acid, and the final amperometric titration is made with ammonium paramolybdate as titrant.

Separation and purification of thorium from monazite leach liquors was investigated by counter current extraction process. The Primene JM-T (mixture of highly …

Monazite is a RE–thorium phosphate, in which high content of a. naturally occurring radioactive element presents a negative aspect. ... in ilmenite hinders the separation of monazite. But ...

Tin smelting process produces waste in the form of large amount of slag II. Slag II still consist of major elements such as 0.0619% uranium, 0.530% thorium, 0.179% P2O5 and 6.194% RE total oxide ...

Large amounts of thorium are commonly found in monazite which even can be up to 20%. Bastnasite usually hosts small amount of uranium and often certain amount of thorium. There is another kind of rare earth resources, ion-adsorption clays mainly found in China. ... The thorium separation from rare earths in the process is shown in Fig. 2 …

The mean concentrations of thorium and uranium in Malaysian monazite are presented in Table 1. The activity concentrations of thorium and uranium were 15258.14 ... View in full-text. Context 2.

stage digesting monazite with hot sulphuric acid and separation percentage of thorium from REEs in monazite leach solution was 97.6 8 % using selective precipitation by ammonia. The optimum ...

Thorium has a special interest in the future nuclear energy as a fuel especially the breeder reactors. The present research has been fulfilled throughout successive research schedule manner on separation and purification of thorium from Egyptian beach monazite mineral after its acid digestion. Monazite mineral was …

A major source of rare earths is monazite sand, which is found on many beaches in Brazil and India. Monazite is particularly rich in cerium. The typical composition of monazite sand is as follows and can be considered a rare earth, thorium phosphate: CeO 2 30%. Di 2 O 3 (mixed lanthanides) 32%. ThO 2 6.50%. P 2 O 5 28%. SiO 2 1.50%

Solvent extraction is a powerful separation technique in the preparation of nuclear grade thorium. In this study, monazite thorium concentrates produced from Malaysian monazite were used. Thorium ...

The recovery of thorium from the monazite-apatite veins that form the Steenkampskraal deposit in South Africa is being considered (Fig. 10.3), ... The separation of hafnium from zirconium is the key of the nuclear grade zirconium production. Most of the commercially used separation methods are hydrometallurgical routes, including fractional ...

study the methods of production and the properties of thorium metal and thorium compounds (3^5). The only commercidl source of thorium Is monazlte sands. In which the thorium …

The thorium concentrations in the aqueous solutions were determined using ICP-MS -ELAN 9000 (PerkinElmer SCIEX).There are two main parts of the process: Digestion of monazite with hot sulphuric ...

The mineral monazite, a uranium- and thorium-rich phosphate of a rare-earth element (REE), is a common accessory mineral in a variety of felsic igneous rocks and is a common trace constituent in many metamorphic rocks, particularly metapelites. Because of its high uranium and thorium content, and fairly low common lead content, it has often ...

The extraction of thorium involved four stages: digestion, separation, purification, and calcination. Digestion was done by leached the monazite with hot …

Extraction of Thorium from Monazite Ore Emily Watson [email protected] Jacob Reynolds [email protected] Victoria Molotoka [email protected] ... The process relies on the easy separation of thorium from the mixed REE stream since thorium sulfate is solid at 57°C, while the mixed REEs remain in solution. Figure 1 shows the block flow

Recovery of Thorium • Th can be extracted as co- or by-product of rare earth elements (REE) and others, e.g. Nb, Ta. • Monazite in heavy mineral or black sands (placers) may be a major source of Th. • Monazite treated by conc. sulfuric acid, 120-190 0 C, several h, solutions enriched in Th several stages of

Separation and purification of thorium from monazite leach liquors was investigated by counter current extraction process. The Primene JM-T (mixture of highly branched C16 to C22 tertiary alkyl primary amine isomers) was used as an extractant and kerosene as a diluent for the present investigation. Extraction isotherm was plotted at the …

Monazite is composed mainly of rare earth elements in association with radioactive elements such as uranium and thorium. The presence of thorium and uranium with REEs in the monazite mineral increases its radioactivity and is harmful to the environment; therefore, the separation of radioactive elements is of great importance for …