Chapter 298 - 153: Probing

Chapter 298: Chapter 153: Probing

If traditional methods were used for refining, the mining and refining companies would lose their shirts.

In reality, the igneous rock in the North commonly contains apatite; the concentration is just too low to be of any industrial value.

The entire North has at least several hundred billion tons of reserves of igneous apatite, similar to the rock currently beneath Jiang Miao’s feet.

So, how would Jiang Miao solve the problem of extraction costs?

The answer lay in biomining technology.

Biomining is the process of using bacteria and fungi, which have a special affinity for certain elements, to extract and concentrate them from minerals and bodies of water.

For example, the root nodules of leguminous plants are, in essence, a way of fixing nitrogen from the air via bacteria.

Currently, biomining technology is also used to work many low-grade copper deposits.

The advantages of biomining are low energy consumption, environmental friendliness, and the ability to process low-grade ore.

Its disadvantages include relatively low efficiency, the need for specific cultivation and reaction tanks for the microorganisms, and the fact that bacteria and fungi capable of efficiently concentrating specific elements are rare and difficult to cultivate artificially.

This, however, was precisely where Jiang Miao excelled.

His extraction plan was to drill wells and inject an extraction solution containing specific bacteria and nutrients. The bacteria would then proliferate wildly within the surrounding strata, concentrating the phosphorus from the rock. The extraction solution would then be pumped out periodically, and the nutrient solution replenished.

The well would be abandoned once the phosphorus content in the surrounding subterranean rock layers was reduced to approximately 0.3%.

Jiang Miao had experimented with over a dozen types of bacteria in his lab.

He had currently selected three types for focused research: *Rhodospirillum rubrum*, *Sphaerotilus natans*, and *Nitrobacter*.

He chose these three because they were non-pathogenic; even in the event of an infection, the risk would be minimal.

Other bacteria, such as those from the genera *Chromatium*, *Beggiatoa*, *Acinetobacter*, *Aeromonas*, and *Pseudomonas*, had to be excluded, as many of them can cause fatal infections in humans and animals.

Jiang Miao was most optimistic about *Sphaerotilus natans*.

*Sphaerotilus natans* is primarily found in flowing fresh water rich in organic matter—such as polluted rivers, filter basins, and activated sludge—and is extremely aerobic.

It has the ability to solubilize phosphorus and potassium. It can also activate secondary elements in the soil, such as silicon, calcium, and magnesium, and increase the availability of iron, manganese, copper, zinc, molybdenum, and boron. This improves or extends fertilizer efficacy, reduces the need for chemical fertilizers, enhances crop stress resistance, and prevents or mitigates diseases. Moreover, as it grows and reproduces, it can produce organic acids, amino acids, polysaccharides, hormones, and other substances beneficial for plant absorption and utilization.

Therefore, injecting *Sphaerotilus natans* into the wells would avoid causing serious pollution. When it was time for them to concentrate phosphorus, an air pump would introduce air into the well. If they were no longer needed, the nutrient solution could be cut off and the wellhead sealed, which would suffocate the *Sphaerotilus natans* underground.

Moreover, *Sphaerotilus natans* could concentrate not only phosphorus but also potassium, killing two birds with one stone.

Unlike the phosphorus and potassium extracted through traditional industrial methods, the product derived from *Sphaerotilus natans* was essentially an organic fertilizer. After adjusting the phosphorus-to-potassium ratio, it could be sold directly as such, eliminating another step in the process.

The only remaining hurdle was that cultivating *Sphaerotilus natans* was rather difficult.

Isolating and purifying the bacterium was quite difficult. The typical method involved enrichment culturing in a low-nutrient medium. While labs commonly used liquid preservation, other options included simple preservation methods or cryopreservation in liquid nitrogen.

Fortunately, Jiang Miao could determine the various characteristics of *Sphaerotilus natans* by analyzing its genetic sequence.

He used agar as a culture medium, added some specific ingredients, and then inoculated it with a starter culture of *Sphaerotilus natans*. After allowing it to proliferate for three days, he used a freeze-drying process to create starter culture blocks.

These blocks had a long shelf life when stored in a sealed, pure nitrogen environment, facilitating the mass production and deployment of the *Sphaerotilus natans* starter culture.

The application process was simple: drop the culture block into water, add a specific nutrient powder, and aerate the mixture. In the higher temperatures of summer, the bacteria could multiply rapidly in just a few hours. Finally, the resulting *Sphaerotilus natans* extraction solution was ready to be injected into the well.

Jiang Miao’s simulations showed that with the support of a specific nutrient solution, it would only take about 10 days for the *Sphaerotilus natans* to absorb the phosphorus within a surrounding 3- to 5-meter radius. By then, the bacterial population in the extraction solution would have reached its maximum density, signaling that it was time to pump out the mineral-rich fluid.

After the bacteria-laden mineral fluid was pumped out, it would be injected into a separation tank. There, ultrasonic waves would be used to herd the *Sphaerotilus natans* into a specific area of the tank.

This was a method Jiang Miao developed after studying the genetics and physical structure of *Sphaerotilus natans* and discovering their high sensitivity and aversion to specific ultrasonic frequencies. By continuously emitting these waves from one side of the tank, the bacteria would actively move away, allowing for a secondary concentration.

The purpose of this step was to conserve water, allowing 95% of the water from the fluid to be reinjected into the well.

The remaining, highly concentrated, bacteria-laden fluid could then be evaporated, either naturally or with heat, to yield crystals rich in phosphorus, potassium, and organic matter.

Using this process, if it could be implemented on a large scale, the average cost to extract one ton of pure phosphorus (equivalent to 2.29 tons of phosphorus pentoxide) would only be about 870 yuan.

Additionally, 50 to 600 kilograms of potassium (equivalent to 95 to 1140 kilograms of potassium chloride) could be extracted, depending on the potassium content of the rock strata.

This cost was comparable to the domestic cost of producing phosphorus pentoxide from phosphate ore. Currently, the domestic production cost for phosphorus pentoxide was about 400 yuan per ton.

Moreover, the *Sphaerotilus natans* biomining technique for phosphorus and potassium caused very little environmental pollution, consumed little water, and didn’t require large-scale blasting, excavation, or extensive mining and smelting equipment.

It was precisely these advantages that brought the technology’s overall cost down to a level comparable with traditional phosphate ore refining methods.

This technology’s advent meant that the country’s industrial phosphate reserves would increase by several hundred billion tons. Even if these phosphate rocks only had a concentration of 2-3%, billions of tons of pure phosphorus could still be extracted.

Based on the current domestic consumption of 20 million tons of pure phosphorus per year, these billions of tons could support the nation’s needs for centuries.

’However,’ Jiang Miao estimated, ’this technology will most likely remain a reserve technology. The country has been trying to reduce the scale of domestic phosphate mining in recent years, looking to solve its supply issues through imports.’

’The authorities will most likely approve a few companies to use this technology but limit its scale. That way, they can ensure a talent pool with the necessary expertise is maintained without resorting to large-scale extraction. If the international situation were to suddenly deteriorate, they could then leverage the talent from these companies to rapidly scale up production.’