Speaker
Mr
Lodoysamba Sereeter
(German-Mongolian Institute for Resources and Technology, Mongolia)
Description
Mongolia is rich in fluorite resources and enriched fluorine is one of
items of mineral export of Mongolia. Sorting fluorite ore on the
input of the enriching factory is an important measure to keep the
enrichment process running smoothly. A determination of fluorine
content in the enriching pulp allows fast control of the enriching
process. Rapid neutron activation technique for fluorine content
determination in the pulp takes $15$ min against the traditional
chemical analysis (one day).
In this paper, devices based on neutron activation technique for
fluorine determination in fluorite ore and enriching pulp in the
factory are described. The first device (Flourite-1) was developed as
a stationary instrument for fluorine content determination in the
fluorite ore at mine. The second device (Fluorite-2) was developed to
determine fluorine content in ore on the lorry to sort ores in the
factory input. Sorting ore on arrival by its content is important for
enriching process control, as ore to the factory arrives from
different mines. The third device (Fluorite 1M) was developed as
stationary (like Fluorite-1) to determine fluorine content in the
enriching pulp to control a enriching process.
All devices use fast neutron activation analysis. Neutron
sources $^{238}$Pu-Be, $^{241}$Am-Be, $^{252}$Cf
were used for nuclear
reaction $^{19}$F$(n,\alpha)$$^{16}$N with measurements
based on detecting the resulting $6.13$ MeV $\gamma$-ray. Coincident
$\gamma$-ray of $5.5$ MeV and $5.11$ Mev are detected which are
released from the samples during the measurement. The $^{16}$N
half-life is $7.35$ s and the $\gamma$-ray intensity is proportional
to the fluorine content (CaF$_2$) in the ore or enriching pulp.
Fluorine content is calculated compared with standard samples.
Regular $150\times100$ mm NaI(Tl) $\gamma$-ray detectors collect the data.
Fluorite-1 is single channel spectrometry system, where samples and
standards are measured in turn using one counter system. Fluorite-2
is a microprocessor controlled system. Neutron activation of the ore
and $\gamma$-ray detection is made by a pneumatic system moving source
and detector to the lorry. Spectrometry amplifier stabilizer was
developed as the detector of device placed outside and amplitude of
detector signal was changing depending on temperature change
(temperature range is $-40^\circ$C to $+40^\circ$C).
Standard $^{137}$Cs sources were used for stabilization,
calibration and control of the measuring system. Fluorite-1M has two
counters to count pulses from standard and the samples in each
counter, which allow to reduce time of measurement.
Fluorite 1M had absolute error less than 1% and it was much needed
for Bor-Undur, Fluorite Enriching Factory, Mongolia during the
economic crisis years 1990–2000, when there were shortage of chemical
components for chemical analysis of the factory. This kind of device
can be used for control of fluorine enriching factory for industry
process control. Especially this kind of device is needed for
purchasing of fluorite ore from individual customers or export in
Mongolia.
| Country/Organization invited to participate | Mongolia |
|---|
Primary author
Mr
Lodoysamba Sereeter
(German-Mongolian Institute for Resources and Technology, Mongolia)
Co-author
Mr
Shagjjamba Dagva
(German-Mongolian Institute for Resources and Technology, Mongolia)
