PLASTERBOARD WASTE TREATMENT AND RECOVERY PLANT GENERAL FRAMEWORK
This is a plant for the treatment and recovery of gypsum-waste, arising from construction and demolition or the production process. Waste material is reduced to dust and separated from foreign bodies: paper, metal nets or plastics and support iron, realising an (SRM) Secondary Raw Material. The output obtained can be reused in the production of new plasterboard, for use as a flame retardant additive in concrete mix, as an agricultural input for improvement of soil characteristics, as filler absorbent for oils and fats along with other uses.
OPERATION PRINCIPLE
Gypsum waste must be stored indoors, preferably with ventilated air, this reduces the humidity content, which should not exceed 15 ÷ 18%. In the first phase of processing, materials are loaded in a hopper, a belt system operator performs the first removal of incompatible foreign bodies, followed by coarse crushing and volume reduction via mechanical hammers.
The conveyor belt, placed under the crusher, and the subsequent lift, convey the obtained material in a second phase of crushing, this process crushes and pulverizes the product, producing dust and Gypsum granules, as well as a first separation of the materials originally agglomerated i.e. the cellulosic fibres of the support panels in the plasterboard. At this point the material passes through the first vibrating sieve, to separate the plaster dust from extraneous materials, as previously indicated.
At this stage, the product is now made up of small pieces of plaster and cardboard supporting material. The latter, encounters a third refining crusher, removing residual fragments of gypsum from the cardboard. The second vibrating sieve allows a double separation, 1st Separation of the gypsum powder only, which is conveyed into the storage tank of the SRM Secondary Raw Material and the fragments of plaster/paper not yet suitable, are recirculated with the 2nd separation, in which the definitive separation of the paper/gypsum fractions takes place.
At the end of the treatment cycle: Gypsum powder of suitable particle size, to be reused as SRM secondary raw material, which is conveyed to the final storage; Processing residues, consisting of supporting materials (paper), which will be conveyed and stored in special containers (for example, a compactor); Any fragments of plaster not yet suitable, will be put back into the treatment cycle again through special dedicated belts.
Within the process is an over belt magnetic separator, extractor, to intercept the presence of ferrous materials destined for other recovery. This system has maximum adherence to both environmental & safety at work. This aspect of the process is completely isolated from the surrounding environment via an airtight box, consisting of sandwich panels in polyurethane, equipped with safety lock alarm accessible primarily, for maintenance and cleaning.
This box also retains dust produced by the process, which is safely exhausted via a series of filters, while ensuring sound insulation in compliance with abatement regulations.
RECOVERY AND STORAGE FINISHED PRODUCT GYPSUM
Gypsum dust obtained by the treatment is conveyed to storage in roll-off containers, suitably covered and insulated, to avoid dispersion of dust into the atmosphere and moisture absorption. The recovered paper is conveyed and stored prior to being baled