A Plant for the Production of Sodium Sulfate

A Plant for the Production of Sodium Sulfate

From Glauberite Deposits of Shari Saltern

(Salah Al-Deen Governorate)

IRAQ

1.  Introduction

The deposits of Sodium Sulfate exist at Shari Saltern, which is 35 Km to the northeast of Samarra City. These natural deposits are a mixture of clays, sand and glauberite crystals (which are a compound salt of Sodium Sulfate and Calcium Sulfate). Pioneer geological and laboratory studies have proved, with no doubt, that these deposits are suitable for the production of Sodium Sulfate. A pilot unit has been constructed at the location of the deposit and has been used for the production of Sodium Sulfate in the period from 1996 until 2003. This production unit has proved the suitability of these deposits for the production of high purity Sodium Sulfate. The available reserves are big and confirmed and can suffice the production of Sodium Sulfate for many decades with high production capacities.

What are needed to be invested are the natural glauberite deposits by constructing a plant for the production of high purity Sodium Sulfate (99.9%) with a capacity of 50000 tons annually.

Depending on previous offers and studies, the investment cost is about 20 million US$ including the designs, supplying the machinery, civil engineering works, installation and assembling works beside experimental operation and training. This cost does not include services and establishments available at the project location, which will be detailed later.

The above indicated cost is only an estimation to give a preliminary idea to the investor. The investor should perform his own studies to determine the investment and operation costs.

2.  Location

The glauberite natural deposits are located at a distance of  35 Km northeast of Samarra City. The locality is connected with the main road of Samarra – Al-Dor by 25 Km long road which has been constructed especially for this purpose by GEOSURV (Figs.1 and 2).

Fig.1: Location of Al-Shari Saltern

Fig.2: Detailed location map of Shari Saltern 

3.  Geology of the Deposit (raw materials)

Glauberite deposits exist at Shari Saltern, which is a depression of 20 Km length and (3 – 5) Km width. These deposits are in the form of mud rich in glauberite  (Na₂Ca (SO₄)₂) which is present in the form of flat crystals mixed with the clays. The thickness of the glauberite-rich layer at the edge of the saltern is zero and increases toward the centre. It was found that the thickness of this layer is about     4.5 m at the distance of 250 m from the edge and 4.2 m at the distance of 500 m from the edge and 4.5 m at the distance of 750 m from the edge and 4.5 m at the distance of 1000 m from the edge. The highest thickness obtained is 6.5 m at the distance of 750 m from the intersection of the vertical first dike and second dike (Figs.3, 4 and 5).

Fig.3: Three dimensional section through the western part of          Shari Saltern

Glauberite crystals differ in their size. They range from fine crystals of 600 microns to coarse crystals of 4 cm. The color of glauberite-rich layer changes from blue to green to grey and red depending on the conditions of sedimentation. The glauberite-bearing layer is overlain by a layer of black mud. The thickness of this mud layer ranges from a few centimeters near the edge to 40 cm at the centre. This layer is saturated with water and its bearing capacity is zero according to the engineering aspect.

The quantity of water in the saltern differs according to the climatic condition where water level may reach 1 m above the deposits in rainy seasons, while in barren winters the saltern is dry and coated by a salty layer. This water evaporates completely in summer leaving a salty layer of ordinary salt containing 87% of sodium chloride and 13% of sodium sulfate. The thickness of this salty layer ranges from a few millimeters at the edge to 10 cm at the centre of the saltern. The content of sodium sulfate in glauberite-bearing mud ranges from         (5.16 – 12.86) %, while the content of glauberite crystals in the mud ranges from (18.58 – 30.49) %.

Table (1) shows these ratios in the main boreholes from         Sh₂ to Sh_5.

Table (2) shows glauberite components for the sample used in the pilot plant production.

Table 1: Content of glauberite crystals in the mud, Na₂SO₄ content in the crystals and thickness of the mud

                                        Table 2: Composition of glauberite raw material

I.R – Insoluble residue

W.O.C – Water of crystallization

4.  Characteristics of the Product

The pilot production of sodium sulfate using glauberite raw material (analysis is shown in Table 2) yielded sodium sulfate with specifications listed in Table (3).

                                    Table 3: Characteristics of the product from the pilot plant

5.  Reserve

The estimated proved reserve exceeds 20 million tons of sodium sulfate. The reserve with more than 10% of sodium sulfate is estimated to be 12.5 million tons. These reserves are enough to cover the production of 100000 ton annually for about 200 years.

6. Mining Conditions

Sodium Sulfate exists in the Shari Lake in the form of crystals mixed with mud. The first stage of production requires extracting the glauberite-bearing mud from the saltern. The highest concentrations of sodium sulfate exist in the lowest area of the lake where the highest level of ground water is found.

Extracting from the lake is performed using dredging because the floor of the lake is loose and saturated with water and does not bear the heavy weight of the special extracting machinery.

7.  Technological Process of Na₂SO₄ Production

The tecnological process can be cited as follows.

1.      Extracting raw materials which consist of mud, fine sand and glauberite crystals.

2.      Washing raw material by mixing well with water, then isolating the coarser glauberite crystals by size classification.

3.      Dissolving glauberite in water to obtain sodium sulfate solution. When mixing glauberite with water, sodium sulfate dissolves and calcium sulphate stays in suspension.

4.      Filtering the solution to separate calcium sulfate and get a sodium sulfate solution free from suspensions.

5.      Cooling the solution of sodium sulfate to allow the crystallization of sulfate in the form of aqueous crystals (Na₂SO₄.10H₂O).

6.      Separating aqueous crystals either by using precipitation or centrifuge.

7.      Redissolving the hydrated sodium sulfate by heating to remove water of crystallization.

8.      Evaporating the water by raising the temperature under vacuum to allow the crystallization of the dehydrated sulfate Na₂SO₄.

9.      Separating the dehydrated sodium sulfate from the solution.

10.       Drying the dehydrated sodium sulfate and sacking them ready for marketing.

To achieve the above process there are many choices. The investor is free to choose what suits him concerning the methods of cooling, the methods of seperation and the methods of obtaining the vacuum.

8.  Feasibility Study Indicators

The big reserves available of glauberite are enough to cover an industry of high capacity and for many decades. The availability of low cost raw material allows the production of sodium sulfate at reasonable costs, which provides high competitive capabilities. There is a domestic demand for sodium sulfate in the industry of detergents, glass paper and other industries and it is expected that these demands will be doubled in the future. The possibilities of exporting the product are granted especially to neighboring countries where most of them import sodium sulfate.

The main consumer of sodium sulfate in Iraq is the industry of detergents, and then comes the industry of paper and glass. In the eighties of the last century, the consumption of detergent industry in Iraq was about 25000 tons of sodium sulfate annually, while the consumption of paper industry was about 5000 tons. Because of the abnormal conditions during the period of blockade and the Gulf War, the consumption declined greatly. It is expected that the consumption of Sodium Sulfate will increase annually to reach in a few years about 20000 tons in the present existing detergents industry. In case of adding new plants of detergent industry (which is an expected possibility because of domestic need), the consumption of sodium sulfate will multiply many times in Iraq.

Neighboring countries, which produce sodium sulfate, are Turkey and Iran, but both countries import sodium sulfate also. Iran imports about 58000 tons annually of sodium sulfate whereas Turkey imports 192000 tons of it annually. Both Syria and Jordan consume about 5000 tons annually.

The only competitive in the region is Egypt, where it produces about 100000 tons annually, yet the Iraqi production has the privilege of shorter transportation. European competition is unlikely to be effective because of the high cost of transportation.

9. Environmental Requirements

The investor should adhere to all environmental requirements and restrictions recognized by competent Iraqi authorities to avoid any negative environmental impact.

10. Legislations

The investor could make use from the provisions of the following laws and adhere to them in case that they can be applied to the project.

a.   The law of investment No.13 for the year 2006 and its modifications.

b.  The law of Mineral Investment No.91 for the year 1988 and its modifications.

c.   Special laws concerning environmental requirements.

Contact Us

For more details, contact us at the following addresses.

1.   Ministry of Industry and Minerals

      Al-Nidhal St., Baghdad, IRAQ

      Telefax 0096418166040   

      e-mail: invest@industry.gov.iq

      Web site: www.industry.gov.iq

2.   GEOSURV – IRAQ

      P.O. Box 986. Alwiya, Baghdad, IRAQ

      e-mail: geosurv@geosurviraq.com

                   quarries@geosurviraq.com

      Web Site: www.geosurviraq.com