Focus on: Gypsum, a Building Block for World Construction

What is gypsum, and how is it mined?

Gypsum is a soft sulphate mineral composed of calcium sulphate dihydrate, and occurs naturally in sedimentary rock. 

Gypsum can be mined using several methods, depending on the deposit location and characteristics. Open-pit mining is common for near-surface deposits, while for deeper deposits, underground mining techniques are used. 

These include room-and-pillar mining – where sections of gypsum are removed while leaving supporting pillars – and longwall mining, which involves the complete extraction of gypsum panels.

After extraction, the raw gypsum is crushed, screened, and sometimes washed to remove impurities. It might then be calcined, a heating process that drives off water molecules, rto produce plaster of Paris.

The ongoing demand for gypsum in construction and agriculture means that gypsum mining operations worldwide are in constant demand.

What are the industrial uses of gypsum?

Gypsum is used extensively across multiple  industrial sectors.

Construction  It is a key component in the manufacture of plasterboard, also known as drywall, used for walls and ceilings in buildings worldwide. It is also used in the production of cement, where it acts as a setting regulator, controlling the hardening process.

Agriculture  Here gypsum is used as a soil enhancer. It helps improve soil structure, enhance water penetration, and provide calcium and sulphur to crops. Farmers apply it to fields to address soil salinity issues and to promote better root growth.

Food and pharmaceuticals  Gypsum plays a role as a dietary supplement and as an ingredient in certain medicines. It is used in brewing beer and in the production of tofu. The material is also used in water treatment processes, where it aids in the removal of impurities.

Paper industry  This uses gypsum as a filler and coating pigment, enhancing the brightness and smoothness of paper products. 

The arts  Gypsum-based plaster of Paris remains a popular medium for casting and moulding.

Which countries produce the most gypsum?

The global gypsum production landscape is dominated by China, which consistently outputs the largest volume annually. The US is the second-largest producer, with most of its production driven by domestic demand from the construction sector.

Iran has also emerged as a major player in the gypsum market, with  substantial natural deposits, while Thailand also ranks among the top producers, with its gypsum industry contributing significantly to the country's mineral export revenue.

Other notable producers include Turkey, Spain, Russia, Mexico and Canada.

The rise of synthetic gypsum, a byproduct of industrial processes, is  beginning to impact the market dynamics for natural gypsum producers.

Gypsum and sustainability issues

The extraction of gypsum presents several sustainability challenges that the mining industry is under pressure to address. Land disturbance is a primary concern, as open-pit mining operations can significantly alter landscapes and ecosystems. This can lead to habitat loss for local flora and fauna, potentially impacting biodiversity in mining regions.

Water management is another critical issue. Gypsum mining can affect both surface and groundwater resources. The extraction process can lower water tables or alter natural drainage patterns, while runoff from mine sites can introduce sediment and other pollutants into nearby water bodies.

Dust from mining and processing activities also pose environmental and health risks, particularly the respiratory health for workers and nearby communities.

The gypsum sector is exploring solutions to these sustainability issues. Some companies are investing in more-efficient extraction technologies, are using closed-loop water systems, and exploring ways to reduce energy consumption. 

There is also growing interest in the use of synthetic gypsum, a byproduct of industrial processes, as a means to reduce reliance on natural gypsum extraction.