Need for transformation of artisanal gold recovery methodology to semi-mechanized apprentice process for enhanced gold production in Gilgit-Baltistan

The Indus River flowing system formed during Mid-Miocene period, i.e. 18 million years ago, enters Gilgit-Baltistan(GB) from Kargil District of India into Kharmang District of GB and after covering a distance of about 450 km. in GB enters in to the Khyber Pakhtunkhwa Province of Pakistan near Basha (Diamer District). About 22 accomplice rivers and hundreds of major tributaries and sub-tributaries together with the Indus River constitute natural drainage system of the entire 70,000 Sq.Km. area of GB.

?Important and major source material suppliers to the system in GB are the diversified rock units of well-established geological segments, i.e. Kohistan-Ladakh Island Arc, Eurasian Plate, Indian Plate and the E-W trending Main Karakoram (MKT) and Main Mantle (MMT) Regional Thrusts together with their mélange zones

Extensive geo-chemical survey in GB region has already been carried out by Pakistan Mineral Development Corporation Islamabad- a public sector mineral exploration and development organization in collaboration with the AusAid spreading over a period of 10 years. The survey has established dozens of target areas within various suits of rock units exposed in the region, which are the potential source rocks for precious and base metals. All the streams and rivers flowing within the aforementioned established target areas have shown anomalous values for gold, silver, platinum, palladium, titanium, tungsten, vanadium, cobalt, tantalum etc. and other base metals and are continuesly contributing these metals and minerals to the placer deposits in the Indus River System since its inception.

Hundreds of thousands of tons of unconsolidated aggregate size material initially formed at the sites of the source rock outcrops through various geological disintegration processes is being transported annually by water and is deposited at the trapping sites of the respective running water channels. Subsequent transportation, re-transportation, deposition and re-deposition cycle ?in the form of placer deposits make these as commercially workable sites for extraction of gold at least on artisanal scale.

Quite a scores of families locally called as “Soneywals” are involved in gold extraction from the Indus River System since the time immemorial but their process is so crude and primitive that hardly 20 to 30 % of the total gold content present at their working site is recovered. They normally remain restricted up to a depth of not more than 20-30 centimeters on the average while collecting the material for initial washing in their hand made wooden washing sluice whereas the gold being the heaviest element tends to settle at the bottom of the material lying at site. Additionally during the washing process fine and ultrafine and sometimes even medium grained free gold due to surface tension is not trapped in their proto type washing devise and escapes with the washed material therefore is re-deposited in to the system again. Another hazardious, detrimental as well threat to almost all types of flora and fauna in this process is the mercury amalgamation which they initially do with bare fingers by vigorously rubbing the mercury mixed concentrate obtained from their vessels. After this rubbing process, gold pregnant amalgam is re-collected from the black sand and heated up in the open air to evaporate mercury whereas the residue left after heating is crude gold. The evaporated mercury instantly resumes its original shape and due to high specific gravity falls on the ground and mixes in to the river bed intoxicating the entire system.

The aforementioned procedure being unhealthy to the human life and a threat to the environment needs to be transformed in to some scientific and environment friendly system with emphasis on deploying/introducing appropriate tools and portable concentrate making semi-automatic machines in to the system. Similarly, the mercury amalgamation process requires either conversion to a close circuit system where the mercury could be re-cycled or totally replace the mercury amalgamation system with some other more safe and more economic system of gold recovery. Although some preliminary laboratory work on gold recovery from the concentrate recommending bottle rolled cyanidation process instead of open mercury amalgamation by the researchers at KIU Gilgit but so far, its implementation is limited to the laboratory level only for academic purposes.

Need of the time is, therefore, to adopt an approach that is based on physical field work followed by supportive laboratory work and pilot plant scale production of gold. For this purpose selection of at least 5?working sites from where gold has already been extracted by the local gold washers shall have to be demarcated. The selected sites are to be properly sampled up to a depth of atleast 10 meters and the concentrate prepared through a well fabricated portable panning machine/trommel and or a manual sluice. Subsequently the concentrate shall be shifted to the laboratory for carrying out chemical tests and further processing up to the stage of gold extraction and final recommendations for setting up an ensured business plan based on the work done.

The project if implemented in letter and spirit will have the following advantages:

i) ?Accelerated and enhanced recovery of gold.

ii) Environment friendly recovery process.

iii) Spreading the process to the adjoining areas community like a cottage industry.

iv) Generation of economic activity for poverty alleviation.

v)?The gold extracted black sand that at the moment is a favorite sought after commodity by the Chiness (being purchased from the "Soneywals" now a days at Rs.1000/kg) shall be made available in bulk for extraction of other precious metals, e.g. platinum, silver, titanium and zircon which are already confirmed through laboratory tests as present in it.