About project
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Potash Exploration and Equipping Project is a national project and works under authority  of
IRAN Mineral production and supply Company.The playa of Khor with an extension of 2000
km2 is in the Central Kavir of Iran near, the khor city is located in  about 310 km east of Naien,
and  40 km Khor in north of the way Khor-Tabas.
Potash exploration and equipping project is being mobilized with the aim of producing
50000 MT KCl, 300000 MT NaCl and 30000 MT Mg(OH)2 annually.
Exploration studies of the playa are done in an extension of 2000 km2 in 1998  by Tousehe
Olum Zamin consulting engineers.

IRAN POTASH
Taking in account the porosity of the salt crust, volume of brine reserve is about 450 Mm3.
This brine contains of Na, K, Mg, Ca, and small amount of SO4 ions and no I and Br has
been detected.To produce yearly 50000 MT KCl from this brine, about 13 km2 solar ponds
are built which 1/3 of them are carnalite ponds and 2/3 are salt ponds.
Two pipelines with diameter of 70 cm are erected in order to transfer brine with maximum capacity of 4000 m3 in hour to the solar ponds.
Providing brine from different parts of the playa is done by means of seapage channels and several excavated wells.
Precipitation of salt and carnalite in the solar ponds will done in separate phases and will be controlled by growing density came from evaporation procedure. The final brine is sent out from carnalite ponds and is brought back to playa again. The salt and carnalite which are settled down in the ponds are transferred to plant after harvesting.
Part of the removed salt is washed at salt-washing plant with the capacity of 300000 annually.
All the process has been  checked by pilot tests in pilot plants in site.
The main building of project is located in Khor city which contains offices, laboratories, and uesthouse.
The pilot plant, meteorology station and researching ponds are also there.
Also 6-mega watt electricity for revenue of manufacturing unites and pumping station is just installed as a power plant and this amount of electricity is now provided by 4 Diesel generators with capacity of 1.5-mega watt each one.
By putting in to operation the plant 400 persons directly and 1000 persons indirectly will work at this project, so these employment will create a great change in the area of Khor and Biabanak.

Prospecting

Potash Exploration Project, has began with prospecting of Brines and Potash- Salt rocks in several parts of IRAN such as Kashan playa, Qom, Hozesoltan, Varzaneh, Degh Sorkh Ardestan, Loot Zangi Ahmad, Khor playa, Sirvan, Rahrahak and Pohl Salt Dom.

After primary studies and comparing the results Khor & Biabanak playa has been selected as the first choice for production of Potash. The work has been managed for the stages of exploration in three part of the playa, Southern, Middle and Northern area.

Geological conditions

In the central part of Great Kavir, there is a Drainage Basin that playa of Khor part of it. Although the Basin is the lowest part, the Khor playa location is on a plateau 600-850 above sea level.
37 percent of Great Kavir is a  Miu-pliocen sedimentary environment that deep impressed erosion shaped it as a flat field. Depression parts of this field on marl and  evaporates formed the small & large playa and the other parts are covered by Alluvial fan and sand hills.

Playa

Great Kavir playa basin can be divided to three separate parts. Suothern basin with an extension of 2000 km2 is near Khor city and it is named " Playa of Khor". This Playa from center to borders can be saperate to three zones: Salt crust, Moistural zone and clay pan.
Taking in account the prosity of the salt crust volume of brine reserve is about 450 million cubic meters. This brine contains of Na, K, Mg, Ca, No3 and small amount of SO4 ions. No I and Br has been detected.






picture of playa
Climate

The climatic conditions at plant location are characterized by the following average values:

Minimum temperature:                average 15C, below 0 C is possible in the 
                                                 month  December, January, February

Maximum temperature:                average > 40C, not below 15C in the
                                                 month July, August, September

Annual rainfall:                            82 liters per m2
Annual sunshine duration:            3300 hours per year
Annual evaporation rate:               2900 liters per m2
Air humidity:                               minimum in July 19%, maximum in January 53%
Wind velocity:                             average 5.6 km/h maximum 67 km/h

Collection Channels

The Brine collection is done in open channel network and Brine wells. The area of the channel is 16 m2 and their total length is about 16 km. The Brine wells will be excavated deeper than the channels. The lower parts of Brine are much more reached of Mg-Ca-K than the upper parts. So for a better quality of brine it's needed to use these wells.
For each well in depth of 10-13 m there will be a pump and the brine will transmit to the channels with concrete and PVC channels. The collected brine is to tansmit to the solar ponds from the pump station via two 8.8 km GFRP pipeline with 700 mm diameter each one.main pump station is located in the North of Khor- Tabas road with the max. capacity of 4000 m3 per hour. At the end of pipeline is a plunge pool to adjustment of the ponds.8 electro pump will work in an area about 725 m2.

channel Ý
pipe line Ý
Solar Ponds

High evaporation rate in Kavir region and poor annual rainfalls are two reasons to use solar ponds for precepitation of salt and carnallite, these two pand products are the main feeds of potash  and salt plants. The ponds have designed considering plant mass ballance for production of 5000 tph potash, sea page pert in floors and walls, evaporation rate, annual rainfalls, brine pump age perts in pumps  and pipe juctions, ect. and finally evaporation pilot tests. There are 8 salt ponds and 6 carnallite ponds13 km2 total area. The brine with a density of 1.218-1.223 and with maximum rate of 4000 m3/h in warm seasons will come from playa to ponds via GFRP pipeline and rocky channels around the ponds.
Evaporation procedure increases the density and decreases the Na content by precipitation of NaCl in salt ponds. When the density reach to 1.340-1.360 the precipitation of carnallite begins and in the end of evaporation process the remaining brine has a density of 1.450 and a high calcium, Magnesium, Nitrate and chloride content. This remaining heavy brine must be back to playa .
The extraction of salt and carnallite from the ponds will be done via heavy machines named Harvesters. The mechanism is very similar to cold planners in asphalt cuttings in road construction. Harvesting for both salt and cornallite  will be in dry condition and loading in the trucks would be done  in the same time of harvesting the truck capacity in to be 10 tonnes.

Potash Plant

After the delivery of the harvested raw carnallite, the crystalline crop is to be intermediately stored at a stockpile.
The carnallite then is to convey via belt conveyor to Mashing-Milling circuite. In this circuit the crystalling crop milled and sieved to under one millimeter and the CaCl2-Content is to dilute.
For an effective KCl production by using the cold crystallization process, above all it is necessary to separate the valuable carnallite crystals from the admixed NaCl as for as possible. The NaCl-Content of 4% is allowed in the feed to the decomposition to ensure the chemical quality of the final product.
To separate the NaCl from Carnallite an inverse flotation process is employed. It means the purified Carnallite obtained in the flotation process as underflow.This After under flow thickening is fed to decanting centrifuge to separate the crystals from the solution. After centrifuging the carnallite crystals contain only short quantities of adherent solution.
then the purified carnallite, is to fed to the decomposition reactor. The decomposition takes place by using pure water and leaching solution from following cold leaching process.
The suspension with drown from the leaching reactor is to centrifuge completely. The wet KCl from the centrifuge goes to the drying and cooling. The whole potash plant from intermediate storage to sacking plant is just in an EPC contract with an Iranian Company named Kahanroba that works with Lorgy Company in Germany have a very close cooperation with EAT and KUTEC for the Detail Engineering.

Wining of NaCl, MgCl2-6H2O, Mg(OH)2, CaCl2 and NO3 solutions asby-products:

NaCl- In a similar quality as it yields from the solar evaporation process in Khor, Sodium chloride becomes recovered from sea water, and above all it is used as table and chemical Industries.

High quality NACL can be won from the raw Sodium choloride- precipitate from the solar ponds in Khor which extensively can be released from the pollutants CaCl2, Ca(NO3)2 and MgCl2 by means of washing with playa brine and water.
The lab. scale and primary pilot test show hope of success. The results show a 99.14% purification on NaCl and the sum of the pollutants Ca, Mg, and SO4 is less than 0.5% .
Mg(OH)2. The possibility of the production of high grade dead burnt magnesia based on raw materials has been studies and proved. In this regard the Basic Engineering for an Mg(OH)2 production plant with a capacity of 30000 ton has been performed, by EAT and KUTEC jointly

The raw material of this plant are circulating solution and NaCl washing solution, both come from potash plant.

Ponds Final Brine- Solar ponds final brine with 1.45 density and high amount of CaCl2, MgCl2 & Ca(NO3)2 is now the case of studies in Investigation Department in Khor. Primary tests show that MgCl2 can be extracted from the brine by using potash solution and production of carnallite in close circuit, in the further stages the extraction of Tachydrite and the CaCl2, 12H2O and finally Ca(NO3)2 by using simple evaporation ponds are under research.