Plastics flotation

Civil Engineering and Geoscience

Werkwijze voor het scheiden van deeltjes in een vloeibaar medium en een inrichting daarvoor

Particles in a fluid medium are separated by feeding a mixture of particles into a separation chamber. The mixture of particles is treated by moving the medium up and down relative to the mixture of particles. A barrier is present above the mixture to restrain the particles. An Independent claim is also included for an apparatus for separating particles comprising (i) a separation chamber (2), having a supply opening (3) for particles to be separated, (ii) a sieve (4) provided above the supply opening for retention of particles, and (iii) a pump (5) for moving a fluid medium up and down relative to the particles to be separatedCivil Engineering and Geoscience

A method and device for the separation of particles

The invention relates to a method of separating a particle fraction from a particle stream making use of gravitational force and which is performed in a fluid. This provides particle fractions that are collected in respective collecting means. According to the invention the fluid and the collecting means are moved in relation to each other defining a relative direction of movement. There are means provided to limit the movement of the particles to be separated with respect to the fluid in the relative direction of movement. The invention also relates to an apparatus for carrying out the method.Civil Engineering and Geoscience

Method of separating particles in a fluid medium and an apparatus therefor

The invention relates to a method of separating particles in a fluid medium, wherein the particles have a density lower than that of the fluid medium. According to the invention the particles are subjected to an up and down moving flow of the fluid medium, whereby a barrier is present above the particles restraining said particles. It appears that with the method according to the invention a particle separation can be performed in a cost effective and quick manner. The invention is in particular suited for the separation of plastics, such as polyethylene and polypropylene. The invention also relates to an apparatus suitable for performing the method.Civil Engineering and Geoscience

Aluminium Scraps Characterisation by Digital Imagig Techniques

Digital imaging techniques according to the increasing computer power open new dramatic perspectives in terms of their possible application in new industrial fields. One of the field where such a technique can be profitably applied is that of industrial waste recycling. In this perspective this paper analyse several procedures, all digital imaging based, autonomously developed, applied and tested for the characterisation of aluminium scraps resulting from the demolition of cars. Such products present different characteristics according to their composition (aluminium alloys) and their previous utilisation (different car components). These differences are enhanced by comminution process and, in some cases, strongly influences the characteristics of the resulting “particles”. In this paper the possibilities offered by the adoption of imag-ing approach to set up classification-recognition procedures, starting from the evalua-tion of aluminium scarps pictorial characteristics, are analysed and critically evalu-ated. All the tests have been performed on aluminium samples as they results after comminution in an industrial car demolition plant

Process and device for the separation of fragments of liberated ferrous scrap from not liberated ferrous scrap fragments by means of a static magnet

The invention relates to a process and device for the separation of fragments of liberated ferrous scrap from not liberated ferrous scrap fragments by means of a static magnet, wherein a mixture of said liberated ferrous and not liberated ferrous fragments is fed onto a continuous conveyor belt which is driven around drums and wherein said magnet is fixed in the drum distant from the feeding point, wherein a magnet is used which is preferably a dipole magnet having magnetic field lines in the separation zone predominantly parallel to the belt surfaceCivil Engineering and Geoscience

Recycling-oriented characterization of polyolefin packaging waste

Packaging waste is one of the main sources of secondary polyolefins. It is essential to characterize polyolefins derived from this waste stream in such way that not only mechanical sorting methods can effectively separate them but also that online sensor systems can quantify them. The characterization methodology is hierarchical, relating all properties of waste particles in any phase of the processing ultimately to the input End-Of-Life products. The present paper documents a pre-concentrate obtained by hand picking of mixed Romanian household waste. Investigations have been addressed to identify the composition of this polyolefin waste stream, to study the polyolefin density distribution, to distinguish the polymer manufacturing methods (i.e.: injection moulding and blow moulding by flake physical properties and finally to perform all the required polymers characterization/identification by Hyperspectral imaging. On the basis of these analyses, polyolefins from packaging wastes can be recycled by density separation and their rheological properties and wall thickness indicate the moulding procedures

The W2Plastics Project Halfway Achievements

The W2Plastics project aims at a fundamental change of the present status of plastics recycling by creating a breakthrough technology for the recycling of polyolefins from complex wastes, i.e., wastes such as Waste from Electric and Electronic Equipment (WEEE), Construction and Demolition Waste (CDW), household waste and Automotive Shredder Residue (ASR). Polyolefin’s are a very important family of polymers, constituting 45% of the total plastics consumption in Europe (EU) and complex wastes provide the vastest, presently unused potential resource of secondary polyolefin’s. In spite of that, only one million ton out of 14 million tons yearly sold in EU is being recycled into high-end applications. Nowadays, Polyolefin recyclers focus mainly on the relatively pure post-industrial or single-product wastes, since these wastes can be made into high-purity product materials by existing and cost-effective process technology. Post-industrial wastes are increasingly exported outside the EU, however, and so the Polyolefin recycling industry and their end-users are forced to look for alternative resources. The European FP7 Project: W2Plastics is developing a number of novel concepts, in particular Magnetic Density Separation (MDS) and Ultrasound process and quality control by HyperSpectral Imaging (HSI), into a new technology to recover highpurity polyolefin’s from complex wastes at low cost. The unique promise of this new concept derives from its ability to accurately separate many different materials in a single process step, resulting in an environmentally friendly and cheap process