The famous Khewra city is famous for having worlds second largest Salt mine; largest by area wise rock salt mine in the world. Official sources told Business Recorder during the visit to the salt mine here on Saturday that the reserves contain rock salt in the form of halite (98 percent) and is said to be of Pre-Cambrian age.
It is estimated that the mine contains more than 82 million metric tons of reserves of rock salt. It has an annual output of around 0.35 million tons of which 60 percent is sold to a soda ash manufacturing factory in Khewra.
The salt is being mined from this location for centuries. However, the British government in 1872 introduced improved mining practices. This factory also pumps out accumulated brine from the mine while Pakistan Mineral Development Corporation (PMDC) also exports salt on order-to-order basis. Pakistan Mineral Development Corporation (PMDC), Ministry of Petroleum and Natural Resources is operating the mine. This factory also pumps out accumulated brine from the mine. PMDC also exports salt on order-to-order basis.
The rock salt is extracted by using pillar and room technique and the total length of tunnels is 40 km. The mine has 12 levels, out of which 6 are below the surface and currently 400 miners were working in the mine.
A portion of Khewra salt mine has been converted into tourist spot by PMDC, where in visitors have an opportunity to visit a portion of tunnel, developed in 1914 at level 06. Restaurants, parking, public health facilities, shops, etc have been constructed by PMDC to facilitate the visitors and more than 250,000 tourist visits the sale mine every year.
PMDC has also constructed a 6 bed Allergically Asthma Resort for people suffering from Allergic Asthma at level 05. Patients who need treatment spend 8-10 hours each day in the resort for 10 days. During night, the patients move to the rest house of PMDC located near the mine.
There are around 25-30 rock salt processing units in the tehsil that are categorized as SMEs. Entrepreneurs who have salt mines on lease mostly own the units. The production process begins with manual separation of edible and industrial grade rock salt. Around 70 percent of salt is of industrial and 30 percent of edible grade. At times sorting is also made on the basis of color for edible salt, of which pink color salt fetches premium price.
The unit operations are mostly "size reduction" and "classification". The salt lumps are crushed by hammer mills and ground (if required) in rotary disc mills and then classified and packed on the basis of grain size. Vibratory and rotary sieves are used for the size classification.
Industrial salt is shipped to textile (dyeing and finishing), leather tanneries, paint, glass units, oil and gas exploration wells, etc. The food grade salt is shipped to salt processing factories, whole sale markets, etc.
Industrial and edible salt is also exported to India, North America, Far East, Europe, Africa, Afghanistan, etc.
The rock salt blocks are also used to make decoration pieces commonly known as "Rock Salt Products". These include lamps, tiles, bricks, vases, figurines, etc. The salt blocks are cut on horizontal cutters, worked on lathes, drilled and fitted with accessories (decorative and functional). These products are mostly for the international markets but a handful companies from the tehsil export them directly, instead these are sold to exporters in Gujranwala, Lahore and Karachi.
Tourists visiting the Khewra salt mine buy these products as souvenirs. The rock salt products are heavy due to specific gravity of salt and product design. The workers do not have any formal training. Entrepreneurs also lack knowledge of international markets, export management, product development, production operations management, etc.
The Salt range in the tehsil has gypsum mineral deposits containing 80-85 percent of gypsum. The gypsum found here is less white than other deposits in the country due to higher impurities. This mineral occurs as a protective layer around the rock salt deposits in the mines. As a low value and abundant mineral, mining is carried out both by PMDC and mines leased to private sector. The area has around 25 million tons of gypsum reserves and around 0.5 million tons are mined each year. Gypsum is used in manufacturing of cement, Plaster of Paris and as recovery reagent for saline soils. Around 25-30 gypsum processing units mostly SMEs are located, mostly on Khewra and Lilla roads. Majority of the factories produce "Plaster of Paris (PoP)" a hemihydrates form of gypsum and sell in the domestic market. PoP finds its utility in paint, ceramics, foundry, construction, etc sectors.