Increasing the amount of waste of all kinds generated by industry and the population is increasingly seeking to develop technologies for processing waste into new raw materials. This so-called circular economy has many advocates among environmentalists and proponents of green politics, but the results are usually economically unprofitable. Profits are made in the field of metals, especially copper and aluminum, and in some cases gold is successfully extracted from electronic waste.
The biggest problem is mixed municipal waste.
In order to transform municipal waste into useful raw materials, it must first be separated into different materials. In some countries, sorting is done by manual separation with the help of people standing next to the conveyor belts and separating the kind of waste for which there are customers.
In Europe, labor is expensive. Just that thet it attempts to sort through robots that recognize various materials, and they sort waste. However, such attempts have been economic unsuccessful for the time being. In some countries, waste is burned to produce electricity, but sometimes leakage of dangerous gases occurs.
This is why environmental lobbyists are increasingly trying to get the population to collect waste separately, plastic in one bin, glass in another, paper in the third, bio-waste in the fourth. This reduces the amount of mixed waste, but increases the cost of disposal. Separate waste collection requires a lot of new garbage cans, of which the most interest is generated by the manufacturers of the garbage cans, which are strongly lobbying for this type of disposal. The problem is those users who put the waste in the wrong bins. If only one percent of users make the wrong choice of bucket, the process becomes economically unprofitable. And the problem is that in many countries there are no buyers willing to pay enough for raw materials to cover the additional costs of separate waste collection. For this reason, citizens have to pay increasing amounts for waste management. This reduces the standard of citizens and the competitiveness of the industry in the international market.
The solution to this major environmental, health and economic problem is in the technology of waste separation by heat.
This technology is a blend of waste incineration technology, radar separation technology of different materials and thermal separation technology of materials having different melting points.
The technological process is very simple.
The waste is inserted into the top of one sloping pipes into which it is inserted by means of a motor-driven coil, so that the waste gradually slides downwards. At the bottom of this tube, the waste ignites and the hot gases move towards the top of the tube.
In doing so, they dissolve some of the waste they pass through.
Part of the dissolved waste moves downwards, where it encounters a series of small openings through which the molten materials exit the tube and fall into the vessels below.
Due to the high temperature, some of the waste is converted into gas and, together with the combustion gases, they reach the top of the sloping tube where they enter the drain pipe that is placed at the top of the sloping tube.
This reduces the amount of waste in the pipe. In this case, if the thickness of the waste layer in the sloping tube is reduced too much, this can be increased by the increased pushing of the waste from above by a spiral, which can be positioned from the top within the part of the tube itself. It is only at the bottom of the pipe where the temperature is too high that this spiral cannot push waste.
If there is a small amount of gases in the gases that can burn, these gases can be burned at the top of the drain pipe in a torch.
If waste containing a lot of high temperature volatile materials is treated then the waste gases can be discharged to the boiler. In the steam boiler, the waste gases are burned and steam is generated which drives the turbine that drives the electricity generator.
Some molten waste fractions that appear in the openings at the bottom of the hair tube are very hot and can ignite in contact with oxygen. In order to prevent this from happening in vessels where molten materials intrude, it is necessary to put water that rapidly cools the liquid, thus producing small balls of different materials.
The temperature is different at different tube levels and different materials are obtained at different tube levels. At the very top we get water that is created by the condensation of water vapor that is produced by combustion at the bottom of the of the furnace.
Different oils appear slightly lower, then fats. Even lower is the molten paraffin coming out of the furnace, followed by various types of plastic. At an even lower level, molten metals, lead, tin, zinc and aluminum appear. After aluminum, molten glass may appear, and liquid iron may appear at the very bottom. At the very bottom of the of the furnace, a combustion process occurs, which depends on the amount of air that is released into the slanting tube.
The ash and slag residues are passed into small wagons, which are transported to landfills where the slag can be stacked on large piles of chemically inert waste. This slag can also be used as a road surface.
Due to the high temperatures that occur in the sloping tube, it must be mostly made of clay bricks, and only at the top can be made of steel. The rate of combustion depends on the composition of the waste and on the amount of air that flows into the furnace from below.
The economic benefit of this kind of waste separation depends on the materials that are inserted into the furnace. Those who process electronic waste would benefit the most, while the economical treatment of municipal waste would be the lowest. The biggest savings in municipal waste would be to reduce the cost of separate collection and disposal at large landfills.