First, the main treatment methods of industrial waste residue from ceramic firing:
1, landfill method It is to fill the waste residue of ceramic industry into pits or depressions, which is conducive to the restoration of landforms and the maintenance of ecological balance. Because the ceramic industrial waste residue is basically non-toxic, landfill will not pollute the environment. The landfill procedure is roughly as follows: ceramic industrial waste residue-transportation-landfill-unloading-thinning and compaction-covering soil-closed site-greening.
The specific practice of ceramic industrial waste residue landfill is roughly as follows: after the ceramic industrial waste residue is dumped into the landfill, it is diluted and compacted by special machinery. After the accumulation thickness reaches a certain requirement, the clay with a certain thickness is covered and compacted, and then the landfill, compaction and covering are repeated until the landfill is full. At this time, the landfill should be closed, including covering 500-600 mm thick natural soil and compacting, and the slope of the closed top surface should not be greater than 20%. Finally, some flowers should be planted on the landfill.
2. Baking-free brick. The main components of polished brick waste residue are brick chips, abrasive chips, abrasive particles and other ridged substances, which have certain physical and mechanical strength. After screening, additives (such as paraffin, asphalt or polymer resin) can be used to make colored baking-free brick products for paving and roof construction.
3. Concrete products. The main components of polished brick waste residue are ridged substances such as brick chips and abrasive particles, which have certain physical and mechanical strength and are suitable for making building fillers, such as concrete products such as cement bricks, drainage pipes and sewage pipes.
Second, the treatment method of aluminum waste residue
At present, the treatment of aluminum waste residue is mainly to prepare industrial aluminum fluoride from aluminate residue.
This patent belongs to fluoride salt industry in the chemical field. The products are aluminum fluoride and ammonium fluoride, in which aluminum fluoride is electrolytic aluminum. Aluminum fluoride is an essential electrolyte in electrolytic cells, which is mainly sold to electrolytic aluminum plants and exports; Ammonium fluoride is an important basic chemical raw material, which is mainly used to extract rare metals.
For every ton of aluminum ingot produced by electrolytic aluminum plant, about 30 kilograms of aluminum fluoride is needed. In 200 1 year, the annual output of ammonium aluminum in China was about 2.8 million tons, and in 2003 it was 5 million tons. It is estimated that it will reach100000 tons in 2008, and the demand for aluminum fluoride will reach 300000 tons.
With the development of rare metal industry, the demand for ammonium fluoride is increasing year by year. At the same time, it can be exported to earn foreign exchange.
Ammonium fluoride can also be converted into ammonium hydrogen fluoride, which can be used as an etchant when producing aluminum profiles in aluminum profile factories. At present, the annual sales volume of ammonium hydrogen fluoride in this industry has reached 20,000-30,000 tons. Production with this patent has great advantages: 1, the raw material is a by-product in the production process of aluminum profile factory, and the price is about 800 ~ 1000 yuan/ton, and the auxiliary material only needs a few kilograms per ton, while the finished product price is 6000 ~ 6400 yuan/ton of aluminum fluoride and 4500 ~ 5000 yuan/ton of ammonium fluoride; 2. The product rate is as high as 95%; 3. Less investment and quick results; This patent is an environmental protection project, and there is no waste residue in the process, only a small amount of wastewater, which can be discharged up to the standard only by simple treatment.
Three, the pharmaceutical industry pollution treatment can use adsorption hydrolysis.
The combined process of adsorption hydrolysis and contact oxidation was used to treat the wastewater from the comprehensive pharmaceutical production process containing artificial insulin. The results show that the biodegradability of wastewater is obviously improved by strengthening the adsorption acidification process. The treatment of contact oxidation greatly improves the treatment rate of pollutants. The stable operation of 1a shows that the treatment effect of this process is stable, and the treated effluent reaches the first-class standard of national comprehensive wastewater discharge standard.
Moreover, if the fixed bed acidification hydrolysis tank is used, the adsorption effect is obvious, the treatment load is greatly improved, and the biofilm formation speed of hydrolysis bacteria is fast. Proper rising flow rate and reaction time can control the biological reaction in the stage of acid production by hydrolysis, without producing methanation, H2S and smelly CH4, and the biodegradability is obviously improved. This process produces less sludge, so far, no sludge bulking has occurred and the remaining sludge has not been discharged. The treatment efficiency is high, and the effluent meets the reuse requirements. Although the two indexes of ammonia nitrogen and animal and vegetable oil in wastewater are low, they still maintain a high removal rate, which verifies the occurrence of synchronous denitrification and miniaturization of effective organic macromolecules in this process.
Fourth, dust treatment methods.
Judging from the present situation of powder spraying recovery devices in China, the commonly used powder recovery processes can be roughly divided into two categories: the first category of recovery devices, the second-level recovery process, represented by cyclone separators and bag recovery devices; The second category, the main recovery process, is represented by the filter element filter.
Both of the above two recycling methods have shortcomings in the use process. Firstly, the recovery efficiency of cyclone dust collector is limited (currently there are diffusion type, long cone type and multi-tube type, etc.). ), a part of fine powder is lost to the bag dust collector of the secondary recovery device, which increases the burden of the bag, so it often appears in the early stage of equipment operation and has good use effect. However, after long-term use, the fine powder layer accumulated on the surface of the cloth bag reaches a certain thickness, making the filter cloth breathable.
Significantly reduced, the resistance of the whole recovery system increased, and the exhaust air volume of the recovery system gradually decreased, resulting in serious powder overflow in the powder spraying room, the environment of the spraying workshop also deteriorated, and there were hidden dangers of deflagration accidents. At present, there are manual, mechanical or pulse back-blowing methods for secondary dust removal of cloth bags, but due to climatic conditions (such as high air relative humidity) and lagging operation management, dust removal can not achieve the ideal effect, and the above problems inevitably occur. The second recovery
Device, filter element recovery device is generally set at one side near the powder spraying room. Filter element type and bag type are only different in filtering materials, and their filtering principle is the same, so the filter element type recovery device also has all the disadvantages of the above bag type. In addition, due to the above shortcomings, the powder concentration in the powder spraying room increases, even exceeding its explosion limit concentration, and it is easy to cause an explosion accident when encountering sparks, and the consequences will be more serious than secondary recycling with cloth bags.
As far as the whole powder spraying process is concerned, the two powder recovery processes mentioned above bring great trouble to the discoloration of the products, because it is very difficult to clean the powder in the bag and filter element. At present, it is also useful to replace a set of cloth bag or filter element recovery device with one color, but this process will bring trouble to enterprises with diverse products to increase investment and replace filter materials, and it is difficult to popularize and use.
In view of the shortcomings of the widely used powder recovery process at present, the author puts forward a new powder recovery process based on years of experience in painting engineering design, that is, a new two-stage recovery process of reflective cyclone dust collector and humidifying dust collector.
Tornado dust collector, also known as cyclone dust collector, not only accelerates the rotation speed of air flow and enhances the centrifugal force for separating dust particles, but also has less turbulence disturbance than cyclone dust collector due to the existence of secondary air flow, so that the separation particle size of cyclone dust collector can be less than 5 Ixm, which eliminates the shortcomings of cyclone dust collector such as back mixing and turbulence in structure, and the dust removal efficiency is higher than that of ordinary cyclone dust collector, which can reach 99.9% under certain conditions.
Reflective cyclone (as shown in figure 1) is one of the cyclones with the lowest pressure loss. Its working principle is that the airflow containing powder is sent to the primary separation chamber of the reflective cyclone as primary air, and rotates downwards, and the rotating airflow rotates downwards to reach the reflecting plate, which is reversed to an upward airflow. At this time, the coarse powder contained in the rotating airflow is separated from the airflow due to centrifugal force and gravity, while the fine powder in the ascending airflow is separated from the rotating airflow. At the periphery of the secondary separator, the secondary air nozzle sprays secondary air at a speed of 60 m/s, which becomes a downward rotating airflow and rotates in the same direction outside the ascending airflow, so that the fine powder is accelerated to the periphery and forcibly taken to the ash hopper by the secondary air.
From the principle of dust collector, it can be seen that the airflow containing powder has been separated and trapped twice from entering the dust collector to being discharged, so its efficiency is high. An electric research institute in China measured that the recovery rate of low-pressure polyethylene powder by cyclone dust collector was 99%.
The second stage of the new process adopts wet dust collector, and its working principle is: the powder that is not collected after the first stage recovery, mainly ultrafine powder below 5um, can not be reused even after recovery, and is sent to the wet dust collector at a certain speed, so that the gas and water are further mixed through the full contact of the powder-containing airflow and the impact at the outlet, so as to achieve higher powder collection efficiency, and at the same time, water can be recycled. The wastewater is discharged after being treated to meet the relevant national standards.
The new process not only runs reliably, but also avoids the trouble of powder cleaning caused by the above two recycling processes, and also brings convenience to powder spraying and ribbon changing.