The Process of Salt Refining By Refineries in India

Salt is a staple ingredient in every kitchen, and its production involves a meticulous refining process to ensure it meets high-quality standards. In India, salt refineries employ advanced technologies and processes to produce pure and high-quality salt. This article explores the detailed process of salt refining in India, highlighting the steps and technologies used by leading salt refineries in India.

Harvesting and Initial Processing

The journey of salt refining begins with the harvesting of raw salt. This raw salt is typically obtained from two main sources: sea water through solar evaporation and rock salt mining.

1. Solar Evaporation: Seawater is collected in large evaporation ponds, where it is left to evaporate under the sun. As the water evaporates, salt crystals form and are collected.
2. Rock Salt Mining: Rock salt is mined from underground salt deposits. Large chunks of salt rocks are extracted and transported to the refinery.

Washing and Purification

Once the raw salt is harvested, it undergoes several stages of washing and purification to remove impurities.

1. Washing: The harvested salt is washed with water to remove dirt, sand, and other impurities. This step is crucial for producing clean, high-quality salt.
2. Brine Preparation: The washed salt is dissolved in water to form a brine solution. This brine is further purified to remove any remaining impurities, ensuring the salt is of high purity.

Crystallization

The purified brine undergoes crystallization to form salt crystals. This is done using two main methods:

1. Vacuum Evaporation: The brine is evaporated under vacuum conditions, which lowers the boiling point and allows for efficient crystallization. This method produces high-purity salt crystals.
2. Multiple-Effect Evaporation: This method uses multiple stages of evaporation to increase efficiency and yield. It is more energy-efficient and produces high-quality salt.

Drying and Grading

After crystallization, the salt crystals are dried to remove any remaining moisture. The dried salt is then graded based on size and quality.

1. Drying: The salt crystals are passed through drying equipment to remove moisture. This ensures the salt is free-flowing and easy to package.
2. Grading: The dried salt is graded into different sizes, such as fine, coarse, and extra coarse. This grading is important for meeting various market requirements.

Iodization and Fortification

In many cases, the refined salt is fortified with iodine and other nutrients to enhance its health benefits.

1. Iodization: Iodine is added to the salt to prevent iodine deficiency disorders. This is done by spraying the salt with a potassium iodate solution.
2. Fortification: In addition to iodine, some salt refineries also add other nutrients, such as iron and folic acid, to further enhance the nutritional value of the salt.

Packaging and Distribution

The final step in the salt refining process is packaging and distribution. The refined salt is packaged into various forms, including bags, boxes, and sachets, ready for distribution and sale.

1. Packaging: The refined salt is packaged using automated machines that ensure hygiene and efficiency. The packaging is designed to protect the salt from moisture and contamination.
2. Distribution: The packaged salt is distributed to various markets, including local grocery stores, supermarkets, and export markets. India’s salt refineries have a robust distribution network that ensures the availability of high-quality salt across the country and beyond.

FAQs About Salt Refining in India

Q1: What is the difference between raw salt and refined salt?
A1: Raw salt is unprocessed and may contain impurities such as dirt and sand. Refined salt undergoes washing, purification, and other processing steps to remove impurities and produce high-purity, clean salt.

Q2: Why is iodine added to salt?
A2: Iodine is added to salt to prevent iodine deficiency disorders, such as goiter and hypothyroidism. It is an essential nutrient that supports thyroid function and overall health.

Q3: How does vacuum evaporation improve salt quality?
A3: Vacuum evaporation lowers the boiling point of the brine, allowing for efficient crystallization and producing high-purity salt crystals. This method reduces energy consumption and enhances salt quality.

Q4: What are the benefits of using refined salt?
A4: Refined salt is clean, free from impurities, and often fortified with essential nutrients like iodine. It ensures better health benefits and is more suitable for consumption compared to raw salt.

Q5: How is the quality of refined salt ensured?
A5: Salt refineries in India adhere to strict quality control measures, including regular testing for purity, iodine content, and the presence of contaminants. This ensures the refined salt meets high-quality standards.