Study shows that Nigeria still imports salt despite having it produced states. The Raw Materials Research and Development Council (RMRDC) has collaborated with stakeholders to halt importation of salt. BINTA SHAMA reports.
Research by the United Nations COMTRADE database on international trade, has it that Nigeria imports salt from Brazil worth $25.51 million 2021.
The numerous benefits, types & uses of salt
Salt is one of the most common mineral resources in Nigeria, Africa, and the world at large. As it is seen and used daily mostly in cooking and in preservation, and also for its health benefits to humans. Salt is of different kinds such as table salt, sea salt, Himalayan pink salt, red salt, smoked salt, black salt, Persian blue salt, grey salt, etc, but in Nigeria, the most popular is table salt and sea salt.
Sodium Chloride (NaCl) which is also known as common salt is the major constituent in salt. It has a boiling point of 1,413 °C and melting point of 801 °C. Salt, also called halite is a mineral that occurs naturally in a crystalline form, it is mostly present in seawater as the principal mineral constituent and is found in large quantities. The processing of salt is done in the salt mines and begins either by the evaporation of seawater naturally or by brine.
By natural evaporation of sea water; the water is collected and placed in shallow ponds in the salt mines where it is allowed to evaporate with the aid of the sun and the wind during which a salt bed is formed on the bottom of the pond. And by Brine method: a solution of salt in water is subjected to electrolysis to get chlorine gas at the anode, hydrogen gas at the cathode and sodium hydroxide left in the solution.
Nigeria is rich in natural brines just like many other African countries. Salt is said to be found in larger deposits in Ebonyi state whose slogan is “the salt of the nation”, other places of deposits includes Abia, Akwa Ibom, Benue, Cross River, Anambra, Imo, Katsina, and Sokoto state. But it is saddening to say that of the rich salt deposit states in Nigeria, that the country cannot boast of one salt processing industry and even spends millions of Nigeria in the importation of salt in the country.
Health benefits of salt
Further study states that salt has different kinds of benefits. For instance, It helps to control the body’s fluid balance, it helps in controlling the functioning of the muscles and the nerves, promotes a healthy weight and fast metabolism when consumed adequately, aids in balancing blood sugar levels and stabilizes irregular heartbeats.
Note that, salt is good for the body and bad too if it is taken in excess as it can cause water retention, heart disease or failure due to an increase in blood pressure.
Uses of salt
Salt, is known specially for the use of cooking and is present in many processed foods. Salt water is used for preserving food and many much more. It’s used in household cleaning, and in the production of bleach, soaps, detergents, and dyes. It can be used also as a health and beauty product. Salt, is also mostly used by industrial companies in the production of plastic, paper, glass, polyester, rubber, and fertilizers.
RMRDC initiatives
According to the Director General RMRDC Professor Hussain Doko Ibrahim, that salt-bearing sediments are of great economic importance as it is the best and cheapest source of salt. “As a result, stakeholders in the minerals sector have called for exploitation of huge salt deposits in the country. The Benue trough is a unique rift feature on the Africa continent which occupies an intra continental position and has a thick compressional folded cretaceous supracrustal fill.
“Stakeholders have highlighted the need for detailed evaluation of brine deposits in the Benue trough as the non availability of technical information on this area had been a major hindrance to the successful development and commercial production of salt in Nigeria. As a result, the Council commissioned a study to trigger commercial production of salt within the study area in order to augment national supply and thereby reduce the pressure on scarce foreign reserves.”
Furthermore, drawing information from the synopsis of some RMRDC projects (2017-2020) on concept, implementation strategy and future outlook. Information gathered, states that the Council sponsored a research project to access the salt deposits and confirm their locations and suitability for use. Detailed assessment and evaluation of the saline ground waters in parts of the Central Benue Trough, was carried during the study. The primary aim of the study was to conduct an integrated investigation into the saline ground waters within parts of the central Benue Trough in order to understand their basic hydro geochemical characteristics and to identify the major processes controlling their concentration and accumulation. Investigations were carried out through the structural interpretation of aeromagnetic data and Landsat imagery to determine the depth to basement, delineate the basement morphology and relief of the basin. Spectral analysis was said to determine the depths to magnetic layers with the log of the radial spectrum of the aeromagnetic field against frequency numbers which yielded results indicating three discernable linear segments giving depths corresponding to magnetic layers from 1.8, 0.7 and 0.3 km. The basin morphology was interpreted as having parallel sets of micro-basins (graben and horst), in agreement with the general features interpreted by earlier workers. Plots on Piper-trilinear diagram were used for the classification of the saline groundwaters as Magnesium-bicarbonate, Calcium chloride, Sodium-chloride, Sodium-bicarbonate and mixed types with Sodium-bicarbonate type being most prevalent. The high concentration of Ca2+, Na+, and HCO in the groundwater is due to the dissolution of plagioclase feldspars and ferromagnesian minerals, carbonate weathering and ion exchange reactions within the sedimentary units.
Observed characteristics and geochemical processes prevalent within the study area indicated that the origin of the saline ground waters was marine and it was found to be related to the embedded fossil seawater within the transgressive marine sediments on one hand, and the disseminated/precipitated salts within the regressive (sandstone/siltstone) interbeds of the Awe Formation, combined with the dissolution and or leaching of disseminated salts, as well as the modification and remobilization of the embedded fossil seawater through water-rock interaction. The study identified high brine prospect zones at Agaza, Keana, Awe, Ribi and Akiri brine fields based on the established fracture systems, basin morphology, results of bromide-chloride comparison with seawater evaporation trajectory, observed characteristics and geochemical processes and field evaluation of the brines.
Equipment fabrication
On the basis of this, the Council collaborated with the Federal Polytechnic, Nasarawa, on the design and fabrication of a thin layer evaporator and a solar dryer to upgrade the indigenous process used by native communities in the area, to add value to raw salt and to promote investment in local salt processing.
The fabrication and test-running of the equipment had been completed, and some modifications carried out to rectify the problems identified during the trial run. A stakeholders’ forum and public presentation of the equipment was then carried out. The forum was followed by a 3-day training programme for women from salt producing communities in Ebonyi, Nasarawa and Kebbi States. A team of officials from National Salt Company of Nigeria (NASCON), a subsidiary of Dangote Plc; Ministries of Science and Technology, Commerce and Industry and Information, Nasarawa State as well as Nasarawa State Investment and Property Development Company have undertaken visits to Awe and Keana salt producing communities to assess the areas identified as most commercially viable for salt prospecting on the basis of the study carried out. Sequel to the study, plans have reached advanced stage for the establishment of salt refining plants in Keana and Azara in Nasarawa State. The salt refinery would serve as a common facility centre to refine the salt produced in various communities within the State. Also, the Council is working towards encouraging investors to build salt refineries in the area to reduce the cost of importation of salt into the country. So far two investors have been identified and the Council is working with them to ensure the project is actualised.
Based on this initiative, it can be said that local technology now exist for the processing of salt in Nigeria. Some of the equipment required includes passive Solar drier, which is made up of chimney, drying chamber, chamber door and flat plate collector. Others are thin layer evaporator; comprising of brine feed tanker, a chimney, fire box and combustion, fire box-door/damper, hot brine thermometer and cold brine. This is being promoted in order to ensure proliferation of salt processing facilities in Nigeria.