An exploration strategy for finding economically extractable Lithium from brines in Pakistan.

Lithium, a soft silvery alkaline metal is considered as the backbone of rechargeable batteries industry. This 'white gold' of 21st century is obtained from two main sources, i.e. underground continental brine deposits and as hard rock mineral ore deposits. Amongst these 2 aforementioned methods, extraction of Lithium from continental brine is considered as preferred source for investors as this process has already been established 30 to 50% less expensive and environmental friendly than its extraction from hard rocks.

On the basis of surface/shallow subsurface sampling shadowed by a remote sensing programme, the USGS geologists have identified 5Nos. of Salars (salt-encrusted depressions that may or may not be the basin of an evaporate lake) in Afghanistan as having significant potential for economically viable evaporative deposits of lithium and boron. All five tested salars have shown anomalous boron and lithium concentrations comparable to surface lithium concentrations reported from South American salars currently being mined for this metal. The USGS geo- scientists consider this finding promising as their collected samples were from the surface or shallow subsurface because of the fact that such samples normally show low lithium concentration as compared to deeper (greater than 10meters) brines. The aforementioned situation is because of the fact that brines are often diluted at the surface by incoming surface and shallow ground waters whereas saturated brines at?depth are too much denser than fresh water or diluted brines where there is little mixing below the top few meters. Accordingly a more comprehensive sampling program has been recommended by the USGS for all the 9nos. of identified salars in Afghanistan that involves collection of multiple brine, salt and sediment samples from at least 10 meters below the salar surface which will confirm the resource potential in each of the respective salar.

On the premise of USGS proposed model for Afghanistan, a similar exploration model for finding lithium can safely be designed for Pakistan as the same geological environments extends in Balochistan and Sind Provinces of Pakistan. In this context in Sindh province alone, about 170nos. of salt lakes, amongst which100nos. are salt producing ones, have been reported. Most of these salt lakes and mines are located in Tharparkar, Sanghar and Umerkot. Some examples of salt mines located in these regions are Al Amin Salt mines, Tepari salt mines (Fig-2) and Khipro salt mines (Fig-3). In Baluchistan Province, there are many salt lakes notable amongst which is the lake Chagi located in Sultan Nokkundi whereas most of sea salt is obtained from Lasbela and the area near Makran’s coast.

Recommendations

Based on the already laid down lithium exploration model for Afghanistan by the USGS, a fast track and cost effective exploration strategy is required to be designed at National Level in Pakistan too. Pakistan Mineral Development Corporation (PMDC) Islamabad, a Public Sector Organization, already mandated for execution of the similar nature of exploratory works in the entire Country, must be entrusted to accomplish the task by following a pre-planned road map with fixed milestones to be achieved. It will be more appropriate to initiate the subject exploration work at the outset in the Chaghi Salt Lake Area, i.e. around Hamun-e- Mushkel locality as shown vide Fig-1 because of close geologically identical environments with those of Afghanistan SALARs already identified by the USGS that subsequently is to be followed in Sindh Province specifically in Achro and Tepari salt lakes (Fig-2 & Fig-3)?