Half the fun getting about to explore the world’s largest Salt Mine at Khewra (Jhelum district) lies in the journey itself that reveal the sight wonder of lush slopes of red and pink hued hill system in the Punjab province, called the Salt Range with its highest peak named Sakaser (1,522 m/ 4,946 feet). Khewra is the final destination to enter the mine, which is located about 160 km from Islamabad, south of Potohar plateau.
The journey en-route Mandra – Dudyal – Chakwal – Bhaun and Choan Saida Shah, exhibit more than 2000 years old historic sites that evidences the past existence of legendary Mahabharata at the KetasRaj Mandir (temple), and while the main temple, according to records, built in 6c AD – the present site, however, is said to be 900 years old. While the origin of the salt range dates back to about 800 million years when geological movement up-thrust the Indo-Gangetic plains into the formation of the Salt Range extending to about 300 kilometers; in the process, a shallow sea was pushed out of existence. Pre-modern history narrate accidental discovery of health giving salt mountain walls in 326BC when ailing horses of a part of troops of Alexander of Macedon were forced to seek refuge, not too far from the site of the infamous Battle of the Hydaspes (Jhelum) River – where Alexander’s troops had a fatal neck to neck fight with the forces of King Poros (Raja Puru) of the Paurava kingdom. The troops noted that after the horses lick multi colored rock walls varying from deep red to pink and off-white to transparent, the ailment was cured and the horses recovered to head to the battlegrounds.
The word went around the locale and the resident Rajas and native Janjua tribe took over the task of salt mining. The rock salt, also called Himalayan Salt, which is about 99% pure halite, in raw form, contains slight quantity of Calcium, Magnesium, Potassium, Sulfates and moisture, with Iron, Chromium, Copper, Lead, Manganese and Zinc.Later, the Mughal rulers (1526-1857) claimed administrative rights and executed commercial activity of excavating salt. Rock salt for human consumption was sold in local bazaars as well as exported to foreign markets, as far as the Central Asian countries for the sole purpose of generating revenue. Under the Sikh reign, the salt became used in food as an ingredient for healthy diet. After the fall of the Mughal Empire, the British monarchy developed the salt mines paving safe access, adopted security measures for the workers, creating channels and levels for systematic excavation and allocated space for storing the salt. According to records, up to 30,000 tons per annum was produced under the British operation.
A week before our intended visit to the salt mine, we had secured permission from Islamabad at the office of the Pakistan Mineral Development Corporation (PMDC), while entry ticket can be paid at the entrance. We reach Khewra, north of Pind Dadan Khan, which is about 288 meters (945 feet) above sea level and come into the mine via the main entry gate. When inside the mine, you will see beautiful alternate bands of red and white color salt. Other tourists’ attractions in the mine include the 50 year old Salt (Badshahi) masjid that is build of multi colored salt rock slabs; a 75-meter-high (245 feet) Assembly Hall; Pul-Saraat: a salt bridge with no pillars over a 25-meters-deep (80-foot-deep) brine pond; replicas of Minar-e-Pakistan and the Sheesh Mahal (Palace of Mirrors in Lahore) in light pink colored salt crystals; a sculpture of Allama Iqbal; “an accumulation of crystals that form the name of Muhammad in Urdu script; miniatures of the Great Wall of China and the Mall Road of Murree. The Salt Mine is also a major tourist attraction of the country with an annual visitation averaging about 250,000. As a concern to public health, a clinical ward with 20 beds was setup in 2007 for the treatment of asthma and other respiratory diseases using salt therapy.
Salt occurs in the form of an irregular dome like structure. There are seven thick salt seams with cumulative thickness of about 150 meters. At places rock salt is 99% pure.From the main tunnel entrance (since 1872), the mine extends about 730 meters/ 2440 feet inside the mountains and has the total length of about 40 km (25 miles). The staggering 17 level Khewra Salt Mine is developed into 1290 meters long tunnels system and has the underground mine covering an area of 110 sqkm. Quarrying is done using the Room and Pillar method; mining only half of the salt and leaving the remaining half to support what is above. The temperature inside the mine remains about 18–20 °C throughout the year.
A network of two foot (610 mm) narrow gauge railway line originated during the British rule is still in use to roll out salt from the mine. Today, the largest source of salt distribution in the country – the Khewra Salt Mine is operated under the PMDC, with a mission to ‘effect actual development, exploration, mining, extraction, separation, smelting, processing, refining, all kinds of metallurgical operations, utilization, transportation and marketing of minerals, metals and precious stones’. The mine produce more than 350,000 tons per annum, it is estimated that the reserves of salt in the mine vary from 82 million tons to 600 million tons.The mine’s output was reported in 2003 to be 385,000 tons of salt per annum, which amounts to almost half of Pakistan’s total production of rock salt. At that rate of output, the tunnel would be expected to last for another 350 years’.By product or salt residue have various industrial uses in the production of polyvinyl chloride, paper pulp, plastics and many other products.
Since the Mughal period, salt from the mine has had been put to artistry, carving out decorative items like lamps, sculptures, trays, vases and exported to some of the Asian countries, the United States, and many European countries.