Juan M Perez

• PhD
• Head of Department at Envirobat España, S.L

The industrial alkaline battery recycling process produces an organic fraction (OF) consisting of waste paper, plastic and cardboard. Currently, this OF is used for energy recovery, given the absence of a successful alternative recycling approach, attributed to its contamination and limited economic value. This study explored the valorisation of th...

Nowadays, Lithium-ion batteries are widely used in advanced technological devices and Electric and Hybrid Vehicles, due to their high energy density for weight, reduced memory effect and significant number of supported charging/discharging cycles. As a consequence, the production and the use of Lithium-ion batteries will continuously increase in th...

F-richterite based glasses in the SiO2-CaO-MgO-Na2O-F system were investigated by X-ray diffraction, differential scanning calorimetry and field emission scanning electron microscopy to ascertain the influence of fluorine content on preferential crystallization mechanism and on the spatial position of crystals developed in the initial steps of glas...

The aim of this research was to evaluate the feasibility of using the vitrification process as an alternative solution to the disposal of a coal fly ash and metallurgical slags in landfills. The starting wastes were characterised in terms of chemical, granulometric, mineralogical, and microstructural analysis. A selected batch composition composed...

The aim of this research was to study the feasibility of producing sintered nepheline glass-ceramic through a fast firing route. The thermal behaviour of the original glass was analyzed by mean of differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The microstructural analysis of glass-ceramic materials was carried out by field-...

A study on the devitrification of fluorophyllosilicate glass precursors is presented. The research has been focused on the early stages of the crystallization process and shows the variation in the crystallization mechanism with increasing the fluorine content. The devitrification process has been studied by means of differential scanning calorimet...

This paper reports on the effect of different contents of fluorine on the thermal stability of glasses in the SiO2-MgO-CaO-Na2O-F system. Four glass compositions, with experimental fluorine contents varying from 2.12 to 4.39 wt. %, were studied using differential scanning calorimetry (DSC). The devitrification behavior was assessed through the eval...

Porcelain stoneware is a strongly sintered ceramic material fabricated from ball clays-quartz-feldspar mixtures. Porcelain stoneware is characterized by its excellent technical and functional properties (low water absorption, high mechanical properties, resistant to chemical substances and cleaning agents, aesthetic possibilities …). These characte...

A study on the devitrification of fluorophyllosilicate glass precursors is presented. The research has been focused on the early stages of the crystallization process and shows the variation in the crystallization mechanism with increasing the fluorine content. The devitrification process has been studied by means of differential scanning calorimet...

Porcelain stoneware is a strongly sintered ceramic material fabricated from ball clays-quartz-feldspar mixtures. Porcelain stoneware is characterized by its excellent technical and functional properties (low water absorption, high mechanical properties, resistant to chemical substances and cleaning agents, aesthetic possibilities …). These characte...

This paper presents the results of a study that analyses the effect of fluorine content on glass-forming ability (GFA), glass stability (GS) and preferred crystallisation mechanism for a series of glasses in the SiO2-Al2O3-MgO-K2O-F system. Three glass compositions, with fluorine contents ranging from 4.50 to 5.70 mass%, were investigated by differ...

This paper presents the study of the devitrification of glasses based on the composition of richterite with different fluorine contents. The mechanism of crystallization of glass samples was studied in two different granulometries: powder (<63 microns) and fragment (~3x3x4 mm) by subjecting them to thermal treatments. Crystal phases developed and i...

Moulding pressure and thickness are pre-fixed variables in the porcelain stoneware tile industry. This paper examines the effect of both parameters on technological and microstructure properties of unfired and fired porcelain stoneware bodies. The moulding pressure in unfired tiles has a noticeable effect on bending strength and load borne. Common...

This paper provides the results of a study that examines the effect of fluorine content on glass stability (GS) and the crystallisation mechanism for a series of glasses in the SiO2-CaO-K2O-F system. Four glass compositions, with fluorine contents ranging from 2.51 to 5.63 wt. %, were analysed by differential scanning calorimetry (DSC). The evaluat...

Understanding the crystallization mechanism of a wollastonite base glass using isoconversional, IKP methods and master plots. Abstract The complex development of crystals found in the crystallization of a SiO 2 -Al 2 O 3 -CaO-Na 2 O glass has been explained using Differential Thermal Analysis. The crystal growth process has been studied using isoco...

The present paper shows the results of a nucleation and crystallisation study of a Na-fluorrichterite glass carried out by dynamic scanning calorimetry (DSC). The kinetic study was performed using different procedures (Kissinger, Matusita-Sakka and Kissinger-Akahira-Sunose (KAS) methods), and the Avrami parameter was determined from the Ozawa and M...

A thermal stability and kinetic study from non-isothermal experiments of a commercial and a lignin-novolac resin mixed with two amounts of curing agent has been done employing thermogravimetric analysis technique. Three kinetic models have been tested: a single heating rate method, such as Coats-Redfern, employing several mechanistic functions and...

The properties of green and fired porcelain stoneware bodies have been studied in samples moulded at different pressures (10, 20, 30 and 40 MPa). In green tiles, higher differences in properties have been found at lower moulding pressure. After the fast-firing process, the tiles have been tested to obtain the technological properties such us lineal...

In this study, the time–temperature– transformation (TTT) cure diagrams of the curing processes of several novolac resins were determined. Each diagram corresponded to a mixture of commercial phenol–formaldehyde novolac, lignin–phenol–formaldehyde novolac, and methylolated lignin–phenol–formaldehyde novolac resins with hexamethylenetetramine as a c...

The growth process of mullite in a porcelain stoneware body has been studied under isoconversional, isokinetic relationship and invariant kinetic parameters. Activation energy for mullite crystallisation of over 589-628 kJ∙mol-1 and a LnA over 50-59 min-1 was obtained. The model was Johnson-Melh-Avrami with n = 1.5. The model chosen implies quick n...

The curing kinetics of lignin-novolac and methylolated lignin-novolac resins were studied using non-isothermal methods employing differential scanning calorimetry (DSC) at different heating rates. The Belichmeier, Ozawa and Kissinger methods were applied, which give the kinetic parameters of the curing process studied. In addition, the model-fittin...

The curing process of commercial phenolic, lignin–phenolic and modified lignin–phenolic–novolac resins with hexamethylenetetramine (HMTA) 9 wt% was studied by differential scanning calorimetry (DSC) and thermal mechanical analysis (TMA). Firstly, a demonstration is provided to show that the resin samples studied are associated with an isoconversion...

In this work two types of lignin-novolac resins have been formulated, partially substituting phenol by softwood ammonium lignosulfonate as filler or extender (methylolated) to study the viability of that substitution when resins will be employed as adhesives in textile felts. A commercial novolac resin was used as reference. Free phenol, free forma...

La sustitución del fenol en las resinas fenólicas es una de las posibles vías para soslayar la repercusión de su coste sobre el precio final del producto. La lignina en principio ofrece buenas expectativas como sustutituto del fenol, debido a su similitud estructural. En este trabajo, se ha estudiado la viabilidad de las resinas novolacas con susti...

The curing kinetics of lignin–phenol–formaldehyde (LPF) and phenol–formaldehyde (PF) resol resins was studied by non-isothermal differential scanning calorimetry (DSC) at different heating rates. The data were fitted by means of the Borchardt–Daniels, Ozawa and Kissinger methods, which allow determining the kinetic parameters of both resins. The ki...