CY1114505T1 - Πυριμαχη συνθεση azs - Google Patents

Πυριμαχη συνθεση azs

Info

Publication number
CY1114505T1
CY1114505T1 CY20131100909T CY131100909T CY1114505T1 CY 1114505 T1 CY1114505 T1 CY 1114505T1 CY 20131100909 T CY20131100909 T CY 20131100909T CY 131100909 T CY131100909 T CY 131100909T CY 1114505 T1 CY1114505 T1 CY 1114505T1
Authority
CY
Cyprus
Prior art keywords
weight
azs
fire composition
zirconia
group
Prior art date
Application number
CY20131100909T
Other languages
English (en)
Inventor
Charles W Connors
Michael W Anderson
Shirish Shah
Original Assignee
Magneco/Metrel, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Magneco/Metrel, Inc. filed Critical Magneco/Metrel, Inc.
Publication of CY1114505T1 publication Critical patent/CY1114505T1/el

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/16Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces
    • C03B5/42Details of construction of furnace walls, e.g. to prevent corrosion; Use of materials for furnace walls
    • C03B5/43Use of materials for furnace walls, e.g. fire-bricks
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/10Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
    • C04B35/101Refractories from grain sized mixtures
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/24Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/10Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
    • C04B35/101Refractories from grain sized mixtures
    • C04B35/106Refractories from grain sized mixtures containing zirconium oxide or zircon (ZrSiO4)
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/66Monolithic refractories or refractory mortars, including those whether or not containing clay
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00Casings; Linings; Walls; Roofs
    • F27D1/0003Linings or walls
    • F27D1/0006Linings or walls formed from bricks or layers with a particular composition or specific characteristics
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00034Physico-chemical characteristics of the mixtures
    • C04B2111/00146Sprayable or pumpable mixtures
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00482Coating or impregnation materials
    • C04B2111/00551Refractory coatings, e.g. for tamping
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3217Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3244Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30Constituents and secondary phases not being of a fibrous nature
    • C04B2235/34Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3418Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54Particle size related information
    • C04B2235/5418Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5427Particle size related information expressed by the size of the particles or aggregates thereof millimeter or submillimeter sized, i.e. larger than 0,1 mm

Abstract

Μία πυρίμαχη σύσταση περιλαμβάνει μία πρώτη ομάδα συστατικών και ένα συνδετικό κολλοειδούς πυριτίας. Η πρώτη ομάδα συστατικών περιλαμβάνει αλουμίνα και ζιρκονία. Το συνδετικό κολλοειδούς πυριτίας παρέχεται σε ποσοστό 5 % κ.β. μέχρι 20 % κ.β. του ξηρού βάρους της πρώτης ομάδας συστατικών. Η πυρίμαχη σύσταση περιλαμβάνει 45 % κ.β. μέχρι 75 % κ.β. αλουμίνας, 15 % κ.β. μέχρι 30 % κ.β. ζιρκονίας, και 10 % κ.β. μέχρι 30 % κ.β. πυριτίας.
CY20131100909T 2007-06-19 2013-10-16 Πυριμαχη συνθεση azs CY1114505T1 (el)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/820,390 US8505336B2 (en) 2007-06-19 2007-06-19 AZS refractory composition
EP08771251.9A EP2167434B1 (en) 2007-06-19 2008-06-17 Azs refractory composition

Publications (1)

Publication Number Publication Date
CY1114505T1 true CY1114505T1 (el) 2016-10-05

Family

ID=40135084

Family Applications (1)

Application Number Title Priority Date Filing Date
CY20131100909T CY1114505T1 (el) 2007-06-19 2013-10-16 Πυριμαχη συνθεση azs

Country Status (16)

Country Link
US (1) US8505336B2 (el)
EP (1) EP2167434B1 (el)
JP (1) JP5656629B2 (el)
KR (1) KR101497729B1 (el)
AU (1) AU2008265801B2 (el)
BR (1) BRPI0813416B1 (el)
CA (1) CA2691078C (el)
CY (1) CY1114505T1 (el)
DK (1) DK2167434T3 (el)
ES (1) ES2425764T3 (el)
HR (1) HRP20130801T1 (el)
PL (1) PL2167434T3 (el)
PT (1) PT2167434E (el)
SI (1) SI2167434T1 (el)
WO (1) WO2008157533A1 (el)
ZA (1) ZA200909051B (el)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201102361A (en) * 2009-07-14 2011-01-16 Ind Tech Res Inst Ceramic powder composition optoelectric device substrate utilizing the same
FR2978140B1 (fr) * 2011-07-20 2013-07-05 Saint Gobain Ct Recherches Canal d'alimentation de verre en fusion
TR201109768A2 (tr) * 2011-10-03 2012-04-24 Tamer Pinarci Bir cam seramik malzeme ve üretim yöntemi.
CN102583956A (zh) * 2012-02-03 2012-07-18 郑州中本窑炉材料有限公司 低气孔玻璃窑蓄热室用砖
FR2987835B1 (fr) * 2012-03-07 2014-03-14 Saint Gobain Ct Recherches Beton auto-nivelant.
US20180141868A1 (en) * 2015-05-07 2018-05-24 Les Produits Industriels De Haute Temperature Pyrotek Inc. Article made from refractory material for contact with a liquid metal or alloy, a method for manufacture, use and method of use of same
US10590283B2 (en) 2016-08-12 2020-03-17 Magneco/Metrel, Inc. Method of providing a protective coating composition for molten aluminum and alkali metal environments
US10233335B2 (en) 2016-08-12 2019-03-19 Magneco/Metrel, Inc. Protective coating composition for molten aluminum and alkali metal environments
US10494305B2 (en) 2017-03-16 2019-12-03 Magneco/Metrel, Inc. Method of making refractory article resistant to high temperature shock and creep
US10429130B2 (en) 2017-03-16 2019-10-01 Magneco/Metrel, Inc. Refractory kiln car resistant to high temperature shock and creep
US9994486B1 (en) 2017-03-16 2018-06-12 Magneco/Metrel, Inc. Refractory composition resistant to high temperature shock and creep
CN106946554B (zh) * 2017-03-31 2020-01-14 巩义市顺祥耐材有限公司 一种无水炮泥
CN109336575A (zh) * 2018-10-26 2019-02-15 淄博工陶耐火材料有限公司 一种含锆再烧结电熔莫来石砖及其制备方法
IT201800010817A1 (it) * 2018-12-05 2020-06-05 Danieli Off Mecc Recipiente per contenere ferro di riduzione diretta (dri)
US20220388886A1 (en) * 2020-08-14 2022-12-08 Owens-Brockway Glass Container Inc. Cast cullet-based layer on wall Panel for a Melter
US11479505B2 (en) 2020-05-22 2022-10-25 Magneco/Metrel, Inc. Chemical-resistant quartz-based casting composition
US11554988B2 (en) 2020-05-22 2023-01-17 Magneco/Metrel, Inc. Method of making chemical-resistant quartz-based concrete
CN112759407B (zh) * 2021-03-09 2022-10-11 广州市白云区石井特种耐火材料厂 耐火材料及其制备方法和应用
CN116253573B (zh) * 2022-12-26 2024-01-26 宜兴瑞泰耐火材料工程有限公司 一种危废炉用刚玉-锆莫来石浇注料

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4013A (en) * 1845-04-26 Machine fqe making match-splihts and arranging them in dipping
US1392317A (en) * 1920-02-24 1921-10-04 Fisher Alfred Brass-furnace
FR1288045A (fr) 1960-10-20 1962-03-24 Agglomérant pour matières réfractaires
FR1307299A (fr) 1961-09-11 1962-10-26 Creusot Forges Ateliers Procédé de fabrication de moules réfractaires pour fonderie de précision
SE317026B (el) 1966-10-05 1969-11-03 Amsted Ind Inc
GB1194158A (en) 1967-06-20 1970-06-10 Nalco Chemical Co Refractory Coating Compositions.
US3567473A (en) * 1968-05-14 1971-03-02 Amsted Ind Inc Composition for making refractory articles
GB1283692A (en) 1968-09-25 1972-08-02 Foseco Int Refractory heat insulating materials
JPS519769B1 (el) * 1970-09-02 1976-03-30
US3885005A (en) * 1973-08-20 1975-05-20 Taylors Sons Co Chas Production of refractory articles by a freezecast process
US4119472A (en) * 1976-09-01 1978-10-10 Corning Glass Works Rebonded fusion-cast AZS refractory grain
US4212680A (en) * 1979-04-30 1980-07-15 Nalco Chemical Co. Thixotropic refractory binder based upon aluminum phosphate gelled silica sols
US4342597A (en) * 1981-03-06 1982-08-03 Weston Research Corporation Coating compositions for liners of molten metal troughs and ladles
DE3507876A1 (de) 1985-03-06 1986-09-11 Didier-Werke Ag, 6200 Wiesbaden Verwendung von zementfreien vibriermassen auf basis von aluminiumoxid und/oder zirkoniumdioxid zur herstellung von verschleissteilen
FR2617835B1 (fr) 1987-07-07 1989-11-10 Vesuvius Sa Composition refractaire pour plaques-tiroirs et son procede de fabrication
JP2601134B2 (ja) * 1993-05-18 1997-04-16 日本碍子株式会社 アルミナ−クロミア−ジルコン系焼結耐火れんが
US5403794A (en) * 1994-04-14 1995-04-04 Vesuvius Crucible Company Alumina-zirconia refractory material and articles made therefrom
JP2920726B2 (ja) * 1994-06-08 1999-07-19 大光炉材株式会社 流し込み耐火物
GB9617010D0 (en) * 1996-08-13 1996-09-25 Shaw Richard D Improved refractory binder
JPH10212158A (ja) 1997-01-30 1998-08-11 Toshiba Ceramics Co Ltd ガラス溶解窯用耐火物
US6158248A (en) * 1998-02-26 2000-12-12 Asahi Glass Company Ltd. Fused-cast-alumina-zirconia-silica refractory, methods of making it and glass melting furnace employing it
DE19845761A1 (de) 1998-10-05 2000-04-20 Morgan Crucible Company Plc Wi Hochtemperaturfester, hochbelastbarer, feinkeramischer, gesinterter Konstruktionswerkstoff, Verfahren zu seiner Herstellung und ein Bauteil aus einem Keramikwerkstoff
FR2832403B1 (fr) * 2001-11-20 2004-07-23 Saint Gobain Ct Recherches Composition refractaire non faconnee, destinee notamment a la realisation de soles d'un four de verrerie
ZA200309168B (en) * 2002-12-10 2004-07-22 Magneco Metrel Inc Refractory system for glass melting furnaces.

Also Published As

Publication number Publication date
US8505336B2 (en) 2013-08-13
JP2010530353A (ja) 2010-09-09
US20080314085A1 (en) 2008-12-25
HRP20130801T1 (en) 2013-09-30
PT2167434E (pt) 2013-09-06
PL2167434T3 (pl) 2014-01-31
JP5656629B2 (ja) 2015-01-21
BRPI0813416B1 (pt) 2018-11-27
KR101497729B1 (ko) 2015-03-02
CA2691078A1 (en) 2008-12-24
BRPI0813416A2 (pt) 2014-12-23
AU2008265801A1 (en) 2008-12-24
DK2167434T3 (da) 2013-08-26
EP2167434A1 (en) 2010-03-31
EP2167434A4 (en) 2011-07-06
SI2167434T1 (sl) 2013-10-30
WO2008157533A1 (en) 2008-12-24
KR20100051596A (ko) 2010-05-17
CA2691078C (en) 2013-09-17
ZA200909051B (en) 2011-04-28
ES2425764T3 (es) 2013-10-17
AU2008265801B2 (en) 2013-09-05
EP2167434B1 (en) 2013-08-07

Similar Documents

Publication Publication Date Title
CY1114505T1 (el) Πυριμαχη συνθεση azs
CY1113223T1 (el) Πυριμαχη συνθεση για κλιβανους τηξης υαλου
CY1116377T1 (el) Αναστολεις της ανθρωπινης πρωτεϊνικης φωσφατασης της τυροσινης και μεθοδοι χρησης
CR10530A (es) Anticuerpos anti-dlla4 y metodos que los usan
AR050254A1 (es) Intermediarios y procesos para preparar dichos intermediarios utiles en la fabricacion de pirrolotriazinas
CR10213A (es) Moduladores de la proteína quinasa aurora
UY27852A1 (es) Difenilazatidinonas cationicamente sustituidas, procedimiento para su preparacion, medicamentos que comprenden estos compuestos y su uso.
EA200800644A1 (ru) Спечённое огнеупорное изделие, обладающее повышенной устойчивостью к температурному шоку
DK2207786T3 (da) 2´-Fluor-2´-deoxytetrahydrouridiner som cytidindeaminasehæmmere
CL2011000285A1 (es) Compuestos derivados de 1-(het)aril-4-fenil-pirazoles; uso de dichos compuestos para combatir plagas de animales; procedimiento para combatir plagas de animales; procedimiento para la preparación de composiciones agroquímicas, y compuestos intermediarios.
CR8377A (es) Derivados de acidos fenoxiaceticos utiles como agonistas dobles de receptor activado por proliferador de peroxisoma
CL2007000595A1 (es) Compuestos derivados de piperidina; composicion farmaceutica y uso para el tratamiento y/o profilaxis de enfermedades seleccionadas entre hipertension, insuficiencia cardiaca congestiva e insuficiencia renal entre otras.
GT200800065A (es) Métodos y composiciones para modular la hemostasia
NO20074002L (no) Androgen reseptor-modulatorforbindelser og fremgangsmater
ATE420842T1 (de) Leichtputzmischung in pastöser form
CR10280A (es) Anticuerpos de la efgl7 y metodos de uso
ECSP077319A (es) Acidos 4-((fenoxialquil)tio)-fenoxiaceticos, y analogos de los mismos
ECSP077320A (es) Acidos 4-((fenoxialquil)tio)-fenoxiaceticos y analogos
CL2004000979A1 (es) Nonapeptidos acilados tipo lysobacitina, composicion que los contiene metodo de preparacion, util como bactericida.
ECSP10010379A (es) Derivados de oxindol sustituido y su uso para el tratamiento de enfermedades dependientes de la vasopresina
EA201000026A1 (ru) Керамическая противопожарная плита и способ её получения
DE60311887D1 (de) Multifunktionelle kationische photoinitiatoren, deren herstellung und verwendung
ATE519818T1 (de) Reversibel thermochrome zusammensetzung
BRPI0514379A (pt) compostos de 2-(amino ou amino substituìdo) fenol-5, 6-substituìdo, composições para tingimento contendo os mesmos, e uso das mesmas
AR035489A1 (es) 4-fenil-1-(1-fenil-ciclohexil)-1,2,3,6,-tetrahidropiridinas sustituidas, procedimientos para su preparacion, medicamentos que contienen estos compuestos y el uso de estas sustancias para la preparacion de medicamentos