Semantic Scholar extracted view of "Thorium: Crustal abundance, joint production, and economic availability" by Brett W. Jordan et al. ... Optimal Monazite Concentration Processes for the Extraction of Uranium and Thorium Fuel Material. ... Using the cumulative availability curve to assess the threat of mineral depletion: The …

The second was to accurately determine the concentration of thorium, which is usually present at very low concentrations. This is hardly surprising seeing as uranium-234 is a minor uranium isotope, accounting for just 0.0055% of raw uranium, and its half-life is so long, meaning only a fraction will have decayed to thorium-230.

Abstract A review of the world data on the concentrations of thorium activity concentrations in soils, the atmosphere, surface waters, and bottom sediments is presented. It is shown that in the areas with normal radiation background the 232Th concentrations vary from 5 to 95 Bq/kg in the soil, from 1.0 × 10–5 to 1.0 × 10–2 Bq/L in …

This paper provides an economic assessment of thorium availability by creating cumulative-availability and potential mining-industry cost curves, based on …

The concentration of thorium is significantly reduced from 19.90 mg/L to 1.4 μg/L when the mixed Cextrant 230 and Cyanex 923 was adopted as extractants, while it …

With increasing pH and Th concentration it forms thorium nanoparticles or the so-called colloids. Th ... . d 50 is known as the median diameter and it is the value of the particle diameter at 50 % in the cumulative distribution. SLS gives weight average molecular weight and second virial coefficient. The light source was a 780 nm, 3 mW …

The concentration of thorium ions in aqueous phase was determined by ICP-OES. The concentration of thorium ions in resin was determined by mass balance. ... It can be observed that after the second adsorption, the cumulative adsorption ability no longer increases, indicating that the CMPSNP has been adsorbed to a saturated state, …

FIG. 3 shows the variation of elemental thorium concentration of an aqueous nitric solution that has been used for washing a floc obtained by the process of the invention ... the inventors having indeed found that cumulative coprecipitation results in an increase in the rate of coprecipitation yield and consequently makes it possible to reduce ...

The concentrations of natural alpha-emitting isotopes of thorium (228Th, 230Th and 232Th) have been determined in 22 sets of human tissue samples obtained at autopsy from Grand Junction, CO and in 10 sets from Washington, DC. Tissues included lung, pulmonary lymph nodes, liver, kidney, bone, a few gonads, spleen and thyroid.

A review of the world data on the concentrations of thorium activity concentrations in soils, the atmosphere, surface waters, and bottom sediments is presented. It is shown that in the areas with normal radiation background the 232Th concentrations vary from 5 to 95 Bq/kg in the soil, from 1.0 × 10–5 to 1.0 × 10–2 Bq/L in …

The 232 Th concentrations in vegetables in regions of a normal thorium background range from 5.0 × 10 –5 to 8.4 × 10 –2 Bq/kg with a geometric mean value of 2.4 × 10 –3 Bq/kg (wet weight). In regions with a high thorium background (thorium mining area in Nigeria), this value is 3.7 × 10 –2 Bq/kg, which is significantly higher than ...

The thorium fuel cycle is often perceived to have limited experience, thereby imposing a barrier to its implementation. Thorium fuel cycles do not have the degree of commercial-scale experience associated with the uranium fuel cycle (especially the use of uranium oxide in a once-through configuration in light- or heavy-water reactors); however …

Thorium is a naturally occurring, slightly radioactive element. It is widely distributed in nature with an average concentration of 10.5 ppm Th in the upper earth's crust. In general, thorium occurs in relatively small number in Th-enriched minerals: thorite, thorianite, monazite, bastnaesite, and thorogummite. However, the main world resources …

The average thorium concentration in the Earth's crust is about 5.6 ppm (or 5.6 mg/kg). The concentration of thorium is higher in the upper part of the Earth's crust, reaching 10.5 ppm, while its average concentration in the lower layers is 1.2 ppm …

Eq. (1) shows that 2 mol of protons are released to precipitate 1 mol of thorium oxalate and Eq. (2) shows that 3 mol of protons are released to precipitate 1 mol of rare earth oxalate, resulting in an excessive acidic solution. Mixed nitrate solution (100 mL) was inserted in a system composed of oil bath, condenser and magnetic stirrer. 1 mol·L …

Thorium is primarily concentrated in highly evolved geologic systems, owing to its high charge/radius ratio, which inhibits incorporation into common rock-forming minerals. A consequence is the...

The activity concentration of 226Ra, 232Th and 40K in samples were found to vary from of 16 ± 0.6 to 62 ± 3.2 Bq kg−1 with an average 30 ± 1.1 Bq kg−1, 24 ± 0.9 to 63 ± 1.3 Bq kg−1 with ...

Thorium occurs as a trace element in common rocks and rock-forming minerals, with concentrations in the range of a few pp b to a few tens of ppm ().Th 4+ has an ionic radius of ∼ 1 Å (similar to that of U 4+).This high charge and radius precludes the substitution of major ions in minerals by Th 4+.As a result, Th 4+ (and U 4+) is not accommodated in …

Thorium is a naturally occurring, slightly radioactive element. It is widely distributed in nature with an average concentration of 10.5 ppm Th in the upper earth's …

Overview This page contains the latest trade data of Uranium and thorium.In N/A, Uranium and thorium were the France's N/A most traded product, with a total trade of N/A. Between 2021 and 2022 the exports of Uranium and thorium grew by 432%, from €20 to N/A. Trade in Uranium and thorium represent N/A of total France trade.. Exports In N/A the export …

The point cumulative semi-variogram (PCSV) method application helps to identify the range, distribution and transport of radionuclide at each sampling station. ... In some areas, thorium has high concentrations of black sand layers on gold bed reefs (Buccianti et al. 2009; World Nuclear Association 2013). Thorium is an element with low ...

Abstract A review of the data on thorium concentrations in the tissues of terrestrial and freshwater organisms is given. It is shown that the concentrations of 232Th vary widely in the tissues of both animals and fish, reflecting environmental thorium concentrations. The thorium concentrations in agricultural animal tissues range from …

The dispersion of the thorium concentration is distinctly greater than that of uranium; ionic radii differences may be the cause. ... Uranium and thorium distributions in accessory zircon from granitic rocks 713 Cumulative frequency Fig. 2. Test for lognormality on probability paper. Lognormality is approximated over a considerable percentile ...

The highest activity concentration found in the food samples was due to 40 K being present in all types of food. Among the other radionuclides, high activity concentrations were found for 210 Pb in beans and salt, 210 Po in fish, 226 Ra and 228 Ra in nuts and seeds. The main food groups that contributed most to the effective dose, in …

cumulative total of 400,000 kilograms of natural thorium/uranium contained as contaminants (in concentrations ranging from 0.05 percent to 1.0 percent by weight) in various rare earth compounds and mixtures." The cumulative total of 400,000 kg was in place well before the 2017 direct transfer of control.

In China, the atmospheric concentrations of uranium and thorium of an associated radioactive area and their PM sizes are rarely investigated. Thus, this study aims to estimate the effective dose of uranium and thorium inhaled by humans in the workplace and the surrounding area. ... The 50% cumulative frequency cutoff point was set in the …

Concentrations of thorium in air, food, and/or drinking water are normally very low and thorium-containing substances are not generally readily absorbed by the body. Wet …

Properties and Dosimetry. The long-lived isotope 232 Th is the parent of a naturally occurring radioactive decay series. The thorium decay series can be considered in two steps: (1) the formation of 224 Ra by the successive decays from 232 Th, and (2) the decay of 224 Ra and its daughters to stable lead ().The isotope Ra (half-life, 3.62 days) is an …

The cumulative concentration of Th 4+ in the organic phase was calculated by summing the concentration difference in each contact. ... The concentration of thorium is significantly reduced from 19.90 mg/L to 1.4 μg/L when the mixed Cextrant 230 and Cyanex 923 was adopted as extractants, while it decreased only to 3.8 μg/L by sole …

... The world's total thorium sources are reported to be about 1,400,000 [5] to 5,307,800 tonnes [6]. According to Jorden et al. [7], an estimated total amount of …