Secondary aluminum processing produces considerable amounts of dross, which cannot be directly exploited for aluminum recovery. The objective of the study was to examine the possibility of "Industrial Co-operation" between an aluminum and a cement industry with considerable exports.
The action aims at the prevention, reduction and integrated management of solid wastes from the production of secondary aluminum. The project develops, in experimental and industrial scale, the re-introduction of industrial materials and solid waste from the production of secondary aluminum from the industry "Aluminum of Viotia", to cement production from the cement industry "AGET".
In this way, the model of the "Industrial Co-operation" contributes to the incorporation of the principles of the sustainable development in the industrial activities of the two industries that participate in the realization of the project.
Only one third of the dross is suitable for aluminum recovery (non-salt drug), while the rest gives alumium oxide, which is classified as toxic and hazardous waste in the European Catalogue for Hazardous Waste, following the Technical Working Group of Basel Convention (Basel Convention,1997).This shows that it is possible to use dross stemming from secondary aluminum processing to substitute raw materials in the raw meal with aluminum oxides, such as bauxite and kaolin. Experimental measurements were carried out in order to characterize aluminum dross, the raw mealand clinker produced with the use of aluminum waste.
Solid waste that end up in landfills from a typical aluminum industry amount in 1000-1500 tn per year. In Athens landfill costs 0,02€/kg. However waste disposal is getting more difficult. Greece produces up to 2500tn of non-salt slag per year and about 10000 tn of salt slag. Salt slag is temporally stored in order to be sent abroad for further processing. The exploitation of non-salt slag is currently examined.
The construction of a special landfill area for the industrial waste is bound to increase considerably the disposition cost. Already in the European Union, the average price for disposal is almost multiplied by ten, whereas in some countries, such as France or Germany, their inactivation before being landfilled has already been imposed.
Aim and Objectives of the Project
The aims of the Project were:
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Development of a complete model for "Industrial Co-operation", through the development of processes linked to the existing production chain.
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Pilot experimental application and evaluation of the model.
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Industrial production of cement, according to the model.
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Economic and environmental evaluation of the model.
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Systematic promotion of the application of the model. Examination of the model.
The innovative elements of the project concern:
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The Industrial Co-operation and the promotion of environmental management.
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The results of the project:
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- Definition of the suitability and the use of waste by the cement industry.
- Development of a new type of fertilizer.
- Segregation of waste by means of sieve equipment for screening.
- Production of cement with use of solid waste in industrial scale.
The continuously increasing and visible danger of the depletion of energy reserves and raw materials that are used in the industrial sector, combined with the continual degradation of environmental quality resulted in the development of models for "Industrial Co-operation". While traditional environmental approaches examine one industrial unit at the time, the model of "Industrial Co-operation" applies a more systematic approach. It attempts a larger, deeper and time-expanded integration/optimisation of the scattered industrial activities and of their environmental effects.
The principal aim is the restructuring of the present systems in order to re-establish and protect the industrially suffering regions, from the environmental point of view, while optimising in the same time the productivity of the related enterprises. Two industries with independent productive procedures participate in the project. The first one is "Aluminum of Viotia", which produces the solid biochemical waste, and faces a gradually more intense problem of it's disposal. The other is the cement industry "AGET", that is obliged to purchase raw materials for cement production, which have the general characteristics of the waste, generated by "Aluminum of Viotia".
The objective of the project was the connection of the two industries, using the re-introduction of the biochemical waste of the first procedure in the productive process of the last one. More specifically, the specific objectives of the project are:
Environmental Objectives:
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Reduction of the disposable load of the hazardous solid waste;
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Similar reduction of the consumption of the natural raw materials that are used nowadays for cement production
Economic Objectives:
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Reduction of the production cost of aluminum
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Reduction of the disposal costs of the solid waste
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Favourable effect on the cost of supply of the raw materials for cement production
Social Objectives:
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Reduction of the required area for the landfill of the solid waste. As it is already known, the location and management of waste, especially the hazardous one, at suitable areas for waste disposal has a tremendous social cost and equivalent social effects.
Workplan
Phase Α: Preparatory Actions and Identification of the Current Situation
In this phase preparatory actions that aim at the analysis of the present state of producion, disposition, quality and suitability of the waste for its use in the cement industry are included. Legislative and institutional situation are also investigated and the environmental effects of the waste are analysed.
Phase Β: Creation and Evaluaton of the technical Solutions
In this phase the effect of the fertilizer's texture and of other parameters of the productive process in the waste characteristics are examined. An experimental production of the final product and a test with respect to the cement's requirements for cement production is realised in order to select the solution, according to which the pilot production of the cement on a industrial scale will take place.
Phase C: Pilot Applicaton
In the last phase of the project the production of waste in satisfactory quantities is realised and an industrial production of cement takes place. The results are evaluated from a technical and an economical point of view. The viability and the total advisability is investigated, as well as the environmental dimension of the solution.
Results
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Model of "Industrial Co-operation" Of Aluminum Processing and Cement Industries. This model of Industrial Co-operation is possible to be expanded after the end of the project in order to cover the entire production of this type of waste (10% of the volume of solid waste in South Greece.
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The cost of the waste disposal, which nowadays is 0.02 €/kg has been minimized.
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The Co-operation has as a direct result of discharging the area of Thriassio Pedio of at least 1000 tn of industrial waste per year, which is going to be characterized as hazardous in the forthcoming future.
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The suggesting project has led to the reduction of the waste volume in the centre of management of industrial waste by 10% (which corresponds to 5000 tn per year).
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There has been a similar reduction of the consumption of the raw materials that are going to be replaced by the waste and which are, nowadays, quarried in order to be used in the cement industry.
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The suggested project can be a model for similar activities, regarding waste of other industrial processes.