Chemical Characterisation of Himalayan Rock Salt

Chamical Evaluation of Himalayan Rock Salt

Abstract

Present study involves the chemical evaluation of rock salt samples collected from the plugging
sites of Himalayan salt (Khewra salt mines and Kalabagh salt mines) for their moisture content, water
insoluble matter, calcium, magnesium, sulphate content and trace minerals such as Fe,Cu,Cd,Pb,As,Ag
and Zn determined by atomic absorption spectroscopy. Moisture content of Khewra and Kalabagh salt
samples ranged from 0.03 wt. % to 0.09 wt. % and 0.06 % to 0.08 %, respectively. Water insoluble matter
ranged from 0.08 wt. % to 1.4 wt. % and 1.5 wt. % to 2.8wt. % for Khewra and Kalabagh salt samples,
respectively. Sulphate content for Khewra salt sample was from 0.39 % to 0.91 % and for Kalabagh salt
mines from 0.75 wt. % to 0.95wt. %. For Khewra salt mines calcium ranged 0.15wt. % to 0.32wt. % and
for Kalabagh salt samples from 0.1 wt. % to 0.27wt. %. Magnesium ranged from 0.11 wt. % to 0.35wt.
% for Khewra salt mines, while for Kalabagh salt samples its range was 0.18wt. % to 0.89wt. %. Trace
metals had the concentration ranges between 0.2 to 1.85 mg/kg for copper; between 0.21 to 0.42 mg/kg
for manganese; between 0.04 to 0.06 mg/kg for zinc; between 0.12 to 0.18 mg/kg for arsenic and between
0.03 and 0.05 mg/kg for lead while cadmium content was either below the methods detection limits or
in very trace amounts. The results show that the concentrations of all the parameters studied are below
the limits set by World Health Organization (WHO) and Food and Agriculture Organization (FAO).
Therefore, it can be concluded from the paper that the Himalayan salt from the plugging sites of Khewra
and Kalabagh salt mines are safe to use.