Technological Institute of Saltillo

Saltillo, Mexico

Technological Institute of Saltillo

Saltillo, Mexico
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Rendon-Angeles J.C.,National Polytechnic Institute of Mexico | Rendon-Angeles J.C.,Research Institute of Advanced Studies | Matamoros-Veloza Z.,Technological Institute of Saltillo | Lopez-Cuevas J.,National Polytechnic Institute of Mexico | And 3 more authors.
International Journal of Mineral Processing | Year: 2016

The conversion reaction of three feedstock particle sizes (< 38-165 μm) of celestine (SrSO4) powders into SrWO4 particles with scheelite structure was investigated in highly concentrated NaOH solutions saturated with the chemical reagent Na2WO4. The hydrothermal treatments were carried out over the range of 150-225 °C for several reaction intervals (1-6 h). The complete conversion of SrSO4 into SrWO4 under non-stirred conditions was found to proceed rapidly on fine SrSO4 particles (< 38 μm) by increasing the concentration of the alkaline fluid, and the conversion to SrWO4 was completed at 200 °C for 6 h in a 5 M NaOH solution. The crystallization of the SrWO4 particles occurred rapidly by stirring the autoclave at a speed of 20 rpm, even when larger SrSO4 particles (165 μm) were hydrothermally converted at a low temperature of 150 °C for 4 h. The conversion was further accelerated by increasing the reaction temperature and employing small feedstock particle sizes, < 38 and 69 μm. The SrWO4 particles morphology resembled a quasi-octahedral shaped and consisted of fine particles with bimodal sizes between 0.9 and 2.5 μm. A typical tendency toward particle agglomeration was observed during the crystallization of the SrWO4 particles, which after the longest reaction intervals produced agglomerates with a size of 50 μm. Bulk dissolution of the mineral SrSO4 powder coupled with a massive precipitation produced the formation of SrWO4 particles. A kinetic analysis was carried out for the conversion of large SrSO4 particles (165 μm) into SrWO4 using the diffusion controlled kinetic model proposed by Jander. The activation energy determined for the global conversion process of the quasi-octahedral shaped SrWO4 particles was 18.30 kJ mol- 1. © 2016 Elsevier B.V. All rights reserved.


Resendiz-Flores E.O.,Technological Institute of Saltillo | Garcia-Calvillo I.D.,Autonomous University of Coahuila
International Journal of Heat and Mass Transfer | Year: 2014

This paper proposes the use of the finite pointset method for the numerical solution of two-dimensional transient heat conduction problems. The strong formulation of the parabolic partial differential equation is directly used instead of the corresponding weak form. Moreover, a numerical comparison between the finite pointset method and the corresponding analytical solutions is reported. © 2014 Elsevier Ltd. All rights reserved.


Resendiz-Flores E.O.,Technological Institute of Saltillo | Garcia-Calvillo I.D.,Autonomous University of Coahuila
International Journal of Heat and Mass Transfer | Year: 2015

This paper presents the application of the Finite Pointset Method for the numerical solution of three dimensional and non-stationary heat conduction problems. The strong formulation of the parabolic partial differential equation is directly used instead of the corresponding weak form. Moreover, a numerical comparison between the Finite Pointset Method and the corresponding analytical solutions is reported. © 2015 Elsevier Ltd. All rights reserved.


Matamoros-Veloza Z.,Technological Institute of Saltillo | Rendon-Angeles J.C.,Research Institute for Advanced Studies of the NPI | Yanagisawa K.,Kochi University | Mejia-Martinez E.E.,Technological Institute of Saltillo | Parga J.R.,Technological Institute of Saltillo
Ceramics International | Year: 2015

The influence of aqueous solutions (deionized water or Na2CO3 solutions, 0.1-0.5 M) and other processing parameters such as temperature (150-250 °C) for preparing hydrothermal hot-pressed TV panel waste glass compacts was investigated to produce porous glass specimens. Waste powdered glass (5 g) from old analog Philips television panels (Mexico) with particle sizes of <38 μm was mixed with various amounts of the selected aqueous solution (5-20 wt%). The TV glass panel particles dissolved in all of the mineralizer solution that were employed, and the behavior was controlled by the amount of aqueous solution added to the glass powder densification stage. The reactions of the glass particles with water or Na2CO3 solutions produced a solid glass phase that included water molecules or Na+ and CO3-2 ions, respectively. The hydrothermal hot press (HHP)-treated glass compacts prepared at 200 °C for 2 h at a constant loading pressure of 20 MPa exhibited a marked expansion after heat treatment conducted at 700 °C for 1 h in an air atmosphere. The expansion of the HHP compacted TV panel glass specimens was further increased for the samples prepared with 0.5 M Na2CO3 solution; these foamed glasses exhibited the lowest apparent densities that varied from 0.309 to 0.319 g/cm3. © 2015 Elsevier Ltd and Techna Group S.r.l.


Moncayo-Martinez L.A.,Technological Institute of Saltillo | Zhang D.Z.,University of Exeter | Zhang D.Z.,Chongqing University
International Journal of Production Economics | Year: 2013

The problem of placing safety inventory over a network, which assembles a product, is a challenging issue in supply chain design (SCD) because manufacturers always want to reduce inventory all over the supply chain (SC). Moreover, the process of designing a SC and then placing inventory, to offer high service level at the lowest possible cost, across a complex SC, is not an easy task for decision makers. In this paper we use the SC representation proposed by Graves and Willems (2000), Manufacturing & Service Operations Management 2 (1), 68-83, where a SC is divided into many supplying, manufacturing, and delivering stages. Our problem is to select one resource option to perform each stage, and based on the selected options to place an amount of inventory (in-progress and on-hand) at each stage, in order to offer a satisfactory customer service level with as low as possible total supply chain cost. A resource option here represents a supplier, a manufacturing plant (production line), or a transport mode in a supplying, manufacturing, or delivering stage, respectively. We developed an approach based on ant colony optimisation (ACO) to minimise simultaneously the total supply chain cost and the products' lead time to ensure product deliveries without delays. What are new in our approach are the bi-objective function and the computational efficiency of our ACO-based approach. In addition, ACO has not been applied to solve the inventory placement problem. As a validation of the model, we: (a) describe a successful application at CIFUNSA, one of the largest iron foundry in the world, and (b) compare different CPU time instances and metrics about multi-objective optimisation. © 2013 Elsevier B.V.


Moncayo-Martinez L.A.,Technological Institute of Saltillo | Zertuche F.,Technological Institute of Saltillo
61st Annual IIE Conference and Expo Proceedings | Year: 2011

In this paper, we developed an ant colony algorithm for minimizing the production cost and lead time of one or more products in an assembly supply chain. The problem solved by this approach is formulated in [1] just to solve the Cost of Goods Sold. We propose to extend the problem so as to minimize, simultaneously, the cost of production and the lead time. In this paper, we introduce a framework to solve the problem by means of a relatively new meta-heuristic called Ant Colony Optimization, specially the Rank-Based Ant System, which has been proved to be an efficient algorithm to solve combinatorial problems. The algorithm was tested using a standard problem reported in literature.


Resendiz-Flores E.O.,Technological Institute of Saltillo | Saucedo-Zendejo F.R.,Technological Institute of Saltillo
International Journal of Heat and Mass Transfer | Year: 2015

This paper proposes the use of the Finite Pointset Method (FPM) for the numerical simulation of heat transfer involving a moving source which are present in welding materials processing. The main ideas behind FPM as well as details of the computational implementation are presented. Numerical results of the simulation of the heat transfer process are reported and compared with those obtained by the finite element method which show that the method is promising for these applications. © 2015 Elsevier Ltd. All rights reserved.


Figueroa G.V.,University of Sonora | Parga J.R.,Technological Institute of Saltillo | Valenzuela J.L.,University of Sonora | Vazquez V.,University of Sonora | And 2 more authors.
JOM | Year: 2016

In recent decades, the use of metal sulfides instead of hydroxide precipitation in hydrometallurgical processes has gained prominence. Some arguments for its preferential use are as follows: a high degree of metal removal at relatively low pH values, the sparingly soluble nature of sulfide precipitates, favorable dewatering characteristics, and the stability of the formed metal sulfides. The Merrill–Crowe zinc-precipitation process has been applied worldwide in a large number of operations for the recovery of gold and silver from cyanide solutions. However, in some larger plants, the quality of this precious precipitate is low because copper, zinc and especially lead are precipitated along with gold and silver. This results in higher consumption of zinc dust and flux during the smelting of the precipitate, the formation of the matte, and a shorter crucible life. The results show that pH has a significant effect on the removal efficiency of zinc and copper cyanide ions. The optimal pH range was determined to be 3–4, and the removal efficiency of zinc and copper cyanide ions was up to 99%. © 2015, The Minerals, Metals & Materials Society.


Resendiz E.,Technological Institute of Saltillo | Moncayo-Martinez L.A.,Technological Institute of Saltillo | Solis G.,Technological Institute of Saltillo
Expert Systems with Applications | Year: 2013

This work presents the application of the Mahalanobis-Taguchi System (MTS) to a dimensional problem in the automotive industry. The combinatorial optimization problem of variable selection is solved by the application of a recent version of binary ant colony optimization algorithm. Moreover, a comparison with respect to binary particle swarm optimization algorithm is also presented and a discussion regarding the numerical results is given. © 2012 Elsevier Ltd. All rights reserved.


Resendiz E.,Technological Institute of Saltillo | Rull-Flores C.A.,Technological Institute of Saltillo
Expert Systems with Applications | Year: 2013

This work presents the application of the Mahalanobis-Taguchi system (MTS) to variable detection in the manufacturing process of automotive pedals components. The combinatorial optimization problem of variable selection is solved by the application of Gompertz binary particle swarm optimization algorithm. Moreover, a numerical comparison with respect to other common version of binary particle swarm and binary ant colony optimization algorithms is presented followed by a discussion regarding the corresponding numerical results. © 2012 Elsevier B.V. All rights reserved.

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