There are three methods of salt production: solar energy, evaporation, and rock mining.
1. Production method of salt
1.1 Solar Evaporation Method
This is the oldest method of making salt. Salt crystals have been used since they were first discovered in trapped seawater pools. Its use is only effective in warm climates where evaporation rates exceed precipitation rates, either
or for extended periods of time, and, where there are steady prevailing winds. Solar salt is usually produced by capturing brine in shallow pools where the sun evaporates most of the water. The concentrated brine precipitates the salts, which are then collected by mechanical harvesters. Any impurities that may be present in the brine are drained and discarded before harvest.
Two types of ponds are used. The first is the concentration pond, where the saltwater from the ocean or salt lake is concentrated. The second, called the crystallization pond, is where the salt is actually produced.
Crystallization ponds range in size from 40 to 200 acres, with salt formations formed over years of deposition. During the salt-making season of four to five months, saltwater flows through these ponds. This is a saturated brine solution that contains as much salt as possible, so when the water evaporates, pure salt crystallizes out of the solution. Natural chemical impurities are returned to the brine source.
1.2 Rock Salt Mining Methods
Morton also used the second oldest method of salt production – underground mining. This is the most dramatic way to collect salt. Large machines travel through huge cave-like passages to perform various operations.
Salt mines are among the safest. They are also the most comfortable places to work. While mine temperatures vary with depth, the average temperature remains around 70° F throughout the year.
Salt may appear in veins, as does coal. Veins are primitive layered salt deposits. Salt can also be found in domes, which form when Earth’s pressure forces salt through cracks in the bedrock from depths of 30,000 or 40,000 feet. They resemble circular plugs that are hundreds of yards to a mile wide. Some domes appear close to the surface. Both domes and veins are mined in a similar fashion. Most of the domes in North America are located south from Alabama to Texas, many of which are underwater in the Gulf of Mexico.
To access the salt mines, miners enter the salt bed along shafts from the earth’s surface. Each Morton mine has two shafts:
One for personnel, and one for lowering materials and equipment into mines, as well as raising mined rock salt to the surface. These shafts are also used to provide miners with a constant supply of fresh air as they work hundreds to thousands of feet below the surface. Most mines are lined with concrete walls called shaft liners.
Salt is mined using the room-and-pillar method. It was removed in a checkerboard pattern, leaving a permanent pillar of solid salt for mine roof support. 45% to 65% of the salt is removed. A bedded deposit may have an average room height of 18 feet, while a dome mine may have a room height of 100 feet.
Often, the first operation is an undercut, where large machines cut a 10-foot- or more-deep groove in the bottom of a solid wall of salt. This leaves a smooth floor for salt after blasting.
Next, drill small holes 10 feet or more deep into the salt wall, and load explosives into the drilled holes. The explosives are then detonated, and hundreds to thousands of tons of rock salt are blasted open and fall onto the deposit.
Equipment is used to load and tow the salt onto the machine, which crushes and transports the salt onto a conveyor belt. The lumps are conveyed to a series of stations for crushing and extra-sized lumps. The salt is then placed in a storage tank waiting to be raised to the ground.
Aboveground processing of rock salt involves screening the mined salt into various saleable sizes through operated screens. After separation, each size is shipped to its individual storage box, waiting to be packaged for shipping or loaded into rail vehicles, trucks, river barges, or lake boats as bulk salt for delivery to customers.
1.3 Vacuum Evaporation Method
Another method of salt production is the thermal evaporation of brine by steam in large commercial evaporators called vacuum pans. The salt produced by this method is very pure and fine in texture and is used in applications that need the highest quality salt.
The first part of this operation is called solution mining. Wells are drilled into the salt deposits at distances ranging from a few hundred feet to 1,000 feet. The wells are connected by the recently developed technique of lateral drilling. Once the wells are connected, solution extraction operations begin: water is pumped into one well, dissolving the salt below, and the resulting brine is discharged to the surface through the other well. It is then piped into large storage tanks for storage.
Next, pump the brine into the vacuum pan. These are huge closed containers under a vacuum about three stories high. They are usually arranged in groups of three, four, or five, each under a larger vacuum than the previous one. The working principle of this series of vacuum pans is very simple: every time the pressure is lowered, the temperature at which the water boils is also lowered. For example, at normal air pressure at sea level, water boils at 212°F. But at 10,000 feet above sea level, the air pressure is much less, and the water boils at 194°F. Vacuum pans can operate down to 100°F
In the vacuum pan process, steam is fed into the first pan. This will cause the brine in the pot to boil. Then use the steam from the boiling brine to heat the brine in the second pot. The lower pressure in the second pot allows the steam from boiling in the first pot to boil the brine in the second pot. The pressure is further reduced in each later disk. This allows the steam from the boiling brine in the previous pot to boil the brine in the next pot. While the boiling operation can be done with one pot, several pots in a row produce more salt per pound of steam, improving energy efficiency.
2. The traditional way of drying salt:
Since ancient times, sea salt production in my country has been based on seawater as raw materials, and the practice of drying salt on the beach and using underground brine. Natural tidal absorption is to allow seawater to flow along the tidal ditch during high tide; dynamic tidal absorption is generally considered appropriate and uses axial flow pumps to introduce seawater, which is unique in that it is not restricted by natural conditions. Seawater is the raw material produced by the salt industry. To ensure the normal implementation of production, we must do everything possible to ensure the supply of raw materials.
But drying salt requires a large area of salt fields. How to increase the unit output of drying salt and increase the income of salt farmers under the same conditions? After a long-term exploration, a very cheap and reasonable method was found. The salt drying pool and the brine pool are all laid with HDPE geomembrane.
Lay HDPE geomembrane pond liners also known as HDPE pond liners or geomembrane pond liners, are non-toxic to plants, fish, and salt. HDPE pond liners are also UV stabilized and resist years of weather and sun damage. The main function of the blue pool liner is to prevent liquid leakage and gas volatilization salt making. Geomembrane pond lining is used in the salt industry such as salt field crystallization pond, brine pond cover, salt film, salt pond plastic film, etc.
When the weather is good, the salt pond where the HDPE Geomembrane is laid can more than double the daily salt output than before laying the HDPE geomembrane, and in general, it can increase 50-70% of the original output.
3. The general process of sun-dried salt:
The production of raw salt by solarization is generally divided into four major processes: absorbing tide, making brine, crystallization, and collecting salt.
3.1. Absorb Moisture
In fact, it is the raw material extraction process for the production of raw salt. Seawater is the raw material for salt production. To ensure normal production, we must do everything possible to ensure the supply of raw materials. At present, there are two ways to absorb the tide, one is the natural tide, and the other is the dynamic tide. Natural tide intake is to allow seawater to flow along the tidal ditch during high tide; dynamic tide intake generally adopts an axial flow pump to introduce seawater, which is characterized by the fact that it is not restricted by natural conditions.
3.2. Halogen
Brine production is carried out in a vast evaporation pond. According to the daily evaporation, the water depth of the evaporation pond is controlled, so that the concentration of brine is increased, and finally concentrated into saturated brine.
3.3. Crystallization
Omit continuous evaporation and concentration of seawater, the concentration of various salts continues to increase. When the salt concentration reaches saturation, it will precipitate in the form of crystals. In a supersaturated solution, the supersaturation of the solution is maintained, and the crystals can continue to grow.
3.4. Salt collection
It is to put the grown salt into piles or.
4. Why do we need HDPE geomembrane for salt Industry?
All the salt ponds and salt brine ponds are constructed with HDPE Geomembrane as deemed appropriate, and the daily salt output of the salt ponds where HDPE Geomembrane is laid can be more than doubled compared with that before the HDPE Geomembrane is laid under good weather conditions. Under normal circumstances, it can increase 60-70% of the original output.
Brine preparation Brine is carried out in a large and wide evaporation pond on a plane or surface of an object. According to the daily evaporation, the water depth of the evaporation pond is controlled, so that the concentration of the brine liquid increases layer by layer, and finally concentrates to reach the highest limit of brine.
A Tanzanian customer contacted us from Google. The customer’s salt field project is relatively large and expressed that he wants to buy HDPE geomembrane because the salt pond salt drying project has many advantages.
5. Advantages of salt geomembrane
5.1. The finished HDPE geomembrane is a black high-strength coil with high wear resistance and light and heat absorption properties. It can absorb and convert natural sunlight into heat energy. Speed up the evaporation rate of water, improve the crystallization and separation rate of salt, and increase the salt production per unit area.
5.2. HDPE geomembrane itself is non-toxic and will not produce harmful substances at high temperatures like PVC material, which ensures the infinite safety performance of finished salt.
5.3. After the HDPE geomembrane is used as the anti-seepage isolation of the salt pool, it is beneficial to maintain the cleanliness of the salt and reduce the impurities, and the sales unit price is high.
5.4. After the HDPE geomembrane is used as the anti-seepage isolation of the salt pool, it is beneficial to the collection of crystalline salt and to increase the output.
5 5. HDPE geomembrane has high strength and wear resistance, high investment, and high return rate, and saves the land-use area of the salt drying field, which has good economic benefits. High anti-seepage coefficient–HDPE geomembrane has the anti-seepage effect that ordinary waterproof materials can’t match. HDPE geomembrane has high tensile strength and mechanical resistance, and its excellent elasticity and deformation ability make it very suitable for the expansion or contraction of the base surface. overcome the uneven settlement of the base surface, the water vapor permeability coefficient K<=1.0*10-13g.cmc cm2.s.pa.
5.5.1. Chemical stability–HDPE geomembrane has excellent chemical stability and is used in sewage treatment, chemical reaction pools, and landfills. High and low-temperature resistance, asphalt, oil and tar resistance, acid, alkali, salt, and other 80 kinds of strong acid and alkali chemical medium corrosion resistance
5.5 2. Anti-aging performance–HDPE geomembrane has excellent anti-aging, anti-ultraviolet, and anti-decomposition capabilities, and can be used in bare hands. The service life of the material is 50-70 years, providing a good material guarantee for environmental anti-seepage.
5.53. Plant root resistance–HDPE geomembrane has excellent puncture resistance and can resist most plant roots
5.54. High mechanical strength–HDPE geomembrane has good mechanical strength, tensile strength at break 28MP, elongation at break 700%
5.55. Low cost and high efficiency–HDPE geomembrane adopts new technology to improve the anti-seepage effect, but the production process is more scientific and fast, so the production cost is lower than that of traditional waterproof materials. Save about 50% of the cost
5.5.6. Fast construction speed – HDPE geomembrane has high flexibility, and has a variety of specifications and laying forms to meet the anti-seepage requirements of different projects. Environmental friendly
5.5.7. Environmental protection and non-toxicity – The materials used in HDPE geomembrane are all non-toxic and friendly materials. The anti-seepage principle is ordinary physical changes and does not produce any harmful substances. It is the best choice for environmental protection, breeding, and drinking water pools.
The geomembrane specifications and prices developed by Shandong Dajin are complete and reasonable. The width is usually 1 meter to 8 meters. When the actual use area is larger than the width of the black geomembrane, the HDPE geomembrane needs to be spliced. Usually, an HDPE geomembrane welding machine is used for hot melt welding.
Tanzania salt field adopts Earth Shield black smooth surface geomembrane lining Parameters:
HDPE Geomembrane Specifications: 1.0mm
HDPE Geomembrane Size Of Each Piece: 5.8*100 meters
HDPE Geomembrane Executive Standard: ASTM GRI-GM13
HDPE Geomembrane The Total Quantity: 19600 square meters
HDPE Geomembrane Size: 0.75 mm
HDPE Geomembrane Size Of Each Piece: 5.8*100 meters
HDPE Geomembrane Executive Standard: ASTM GRI-GM13
The Total Quantity: 255,000 square meters
Its products have the characteristics of good waterproof performance, high lightness, anti-aging, corrosion resistance, non-toxicity, environmental protection, etc. The surface is divided into the smooth type and rough type. The surface is roughened by the introduction of technology, the friction coefficient is large, and the sliding of the covering layer is prevented. Geomembrane has excellent chemical corrosion resistance, high-temperature aging resistance, and oxidation resistance, and can withstand direct sunlight for a long time. Geomembrane has high tensile strength and tear resistance, and has excellent puncture resistance on a rough and hard basis. strong outside. High-temperature aging resistance and anti-oxidation performance can withstand direct sunlight for a long time.
The black geomembrane has high wear resistance and light and heat absorption properties. It can absorb and convert natural sunlight into heat energy. Speed up the evaporation rate of water, improve the crystallization and separation rate of salt, and increase the salt production per unit area. The product quality is safe and friendly, which ensures the non-toxic safety performance of the finished salt. After using HDPE Geomembrane as the anti-seepage isolation of the salt pool, it is beneficial to maintain the cleanliness of the salt and reduce the impurities, and the sales unit price is high. After using the HDPE Geomembrane as the anti-seepage isolation of the salt pool, it is beneficial to the collection of crystalline salt and to increase the output. The anti-seepage geomembrane has high strength and wear resistance, high investment, and high return rate, and saves the land-use area of the salt drying field, which has good economic benefits.
All in all, if you happen to have a salt drying project or have been in the salt drying industry for many years and want to increase the production of salt, then HDPE geomembrane is the best choice. If you are interested in the application of geomembranes in salt production, you can contact us by email (info@earthshields.com), and we will provide you with professional solutions.
