EP0549547A1 - Nassgusssand enthaltend Fettsäure und Triglyceride - Google Patents

Nassgusssand enthaltend Fettsäure und Triglyceride Download PDF

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Publication number
EP0549547A1
EP0549547A1 EP92830679A EP92830679A EP0549547A1 EP 0549547 A1 EP0549547 A1 EP 0549547A1 EP 92830679 A EP92830679 A EP 92830679A EP 92830679 A EP92830679 A EP 92830679A EP 0549547 A1 EP0549547 A1 EP 0549547A1
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EP
European Patent Office
Prior art keywords
sand
fatty acids
weight
lustrous carbon
sands
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP92830679A
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English (en)
French (fr)
Inventor
Athos Rinaldi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Laviosa Chimica Mineraria SpA
Original Assignee
Laviosa Chimica Mineraria SpA
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
Priority claimed from ITFI910309A external-priority patent/IT1252822B/it
Priority claimed from ITFI920101A external-priority patent/IT1262904B/it
Application filed by Laviosa Chimica Mineraria SpA filed Critical Laviosa Chimica Mineraria SpA
Publication of EP0549547A1 publication Critical patent/EP0549547A1/de
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
    • B22C1/24—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of oily or fatty substances; of distillation residues therefrom

Definitions

  • the present invention relates to the field of foundry and in particular to improvements in the composition of green moulding sands. More precisely the invention relates to the use in said compositions of a lustrous carbon supply material of low pollutive capacity, able to increase the flowability and the plasticity of said sands.
  • green moulding sands consisting principally of a refractory framework, which is generally siliceous sand, agglomerated with a clay functioninig as a binder. Bentonite can be used successfully as a clay binder.
  • sands also contain water and, depending on the destination of the mould, particular additives such as carbon additives in the manufacture of iron castings and non ferrous alloys. As known, the presence of the carbon additive allows for a better surface finishing and assists the casting cleaning.
  • the so-called mineral black that is coal was used in powder (100-200 mesh) or in grains (50-150 mesh) obtained from the grinding of the low-grade anthracite.
  • the properties useful for the casting of this additive are derived from an active fraction which is produced from the additive at high temperatures.
  • Said fraction, called "lustrous carbon” is an allotropic state of carbon, optically isotropic, having a microcrystalline structure halfway between those of the amorphous carbon and graphite, essentially bidimensional and obtained on ample surfaces specific from pyrolisis of heavy hydrocarbons emitted from the carbon material during contact with the melted metal.
  • a mineral black having a content of between 30 and 35% volatile substances has a yield of lustrous carbon generally not greater than 10% of its own weight and normally comprised between 6 and 8%.
  • Chemical and physical properties; as well as methods of analysis of the lustrous carbon are broadly described in V.I.Bindermagel, A.Kolors, K.Orths: Procedure for the analysis of the additives to materials for moulds, Giesserei Vol.51,12 Nov., pages 729-730 (1964).
  • substances of synthetic origin can be used (for example polypropylene, cumarone resins, polystyrene, glycerophthalic, resins, gilsonite and pitchy substances, phenolic and hydrocarbonic resins, etc.) which during the fusion process are able to develop lustrous carbon in quantities even greater than 50% of their own weight, and therefore about 10 times greater than that developed from the traditional mineral black. For this reason said substitutive substances for mineral black can be used in proportionately smaller quantities.
  • All the minerals used in substitution for the mineral black are of organic and in particular aromatic nature, with low or no oxygen content, and a high carbon/hydrogen ratio, in order to resemble as much as possible to coal. However, even if in different amounts, they are materials which, for the effect of heat during fusion at about 1000°C, decompose depositing finely broken down carbon on the surface of depositing finely broken down carbon on the surface of the casting and on the surrounding grains of sands.
  • polycyclic and non polycyclic aromatic hydrocarbons and 3-4-benzo-a-pyrene are also formed (the latter being particularly deleterious), developing with the gas during fusion, and polluting often dangerously the air of the work environment.
  • the problem of workability of green moulding sands is also of great interest in casting.
  • the moulding sands are continuosly recycled, reintegrated and regenerated with a quantity of components sufficient to keep its characteristics substantially constant over time.
  • sand which has already been used for making the cores, but which is generally adequately pure after the disintegration of the organic binder as a result of the heat during fusion is often reutilized for the moulding sands. This practice can be used especially in the case of series castings, such as radiators and boilers.
  • the object of the present invention is to improve the composition of green moulding sands with the purpose of both further reducing, and possibly eliminating, from the work environment the pollutants most harmful to health which develop from the lustrous carbon supply materials until now utilized, as well as improving the flowability and the plasticity of the green moulding sands.
  • Another object of the present invention is to provide a method for manufacturing moulds in casting the execution of which results in a reduction of the pollutive load of the work environment and better workability of the green moulding sands.
  • a further object of the present invention is to provide a material, utilizable as an additive for the green moulding sands, which is able on one hand to provide sufficient quantities of lustrous carbon while causing fewer pollution problems than the additives currently used for the same object, and on the other to contribute to improving the flowability, plasticity, and therefore workability, of the green moulding sands.
  • medium-high degree of insaturation is intended as an average number of double bonds comprised between 2 and 3 for each molecule of free fatty acid.
  • the average indicative composition of the materials according to the present invention is:
  • the material according to the present invention is able to develop a quantity of lustrous carbon equal to 35-40% of its own weight and, contemporaneously, that during the fusion process in the gasses of thermic decomposition, emitted in the work environment, 3-4 benzo-a-pyrene is not detected, and the mono- and polynuclear aromatic hydrocarbons are present in much smaller quantities than found with the currently used carbon additives. This is probably due to the presence of insaturations in the aliphatic chain and of other types of bonds such as etereal and estereal which prevent the formation of condensed and non condensed aromatic nuclei.
  • a low content of material according to the present invention is sufficient in the green moulding sand to make it considerably more fluid.
  • Said content is on the order of 0.5-1% of the weight of the sand and in any case not less than 0.2% by weight.
  • the additive according to the present invention confers the following characteristics to the green sands:
  • the material according to the present invention When used in quantities greater than 1% of the overall weight of the sand, it acts as a provider of lustrous carbon, besides naturally maintaining its above-mentioned effect on the workability of the sands.
  • the quantity preferred for this function is comprised between 1.5 and 3.5%.
  • mineral black of a traditional type or one of its substitutes, for instance a petrolic resin the minimum percentage to be added to the sands is normally above 5% and 1% respectively.
  • the percentages of free fatty acids in it are: oleic acid 25-65% stearic acid 0-10% palmitic acid 10-20% linolic-linolenic acid 10-50%
  • a particularly preferred material for the objects of the present invention has a percentage content of free fatty acids as shown in the following table 1: TABLE 1 oleic acid 30% palmitic acid 10% linolic and linolenic acid 30% total content of fatty acids 70% Its other typical properties are the following: freezing point 9-10°C boiling point 240°C apparent specific weight at 20°C 0.900 density at 70°C 0.870 flash point 260°C autoignition temperature 300°C acidity number 50-60 iodine number 90-120 Elementary Analysis carbon about 80% hydrogen about 10% nitrogen 1% sulphur absent oxygen about 10% In table 2 which follows, the analyses of the products of decomposition at 1000°C developed from the material according to the present invention (column A), from an aromatic petrolic resin (column B) and from a normal mineral black (column C) are set forth for the purpose of comparison.
  • the material according to the present invention which is in a liquid form, can be added to the other components of the sand (siliceous sand, binder, water and additives) during the mulling step in the percentages defined above, or it can be added in the form of a premix with the binder, with or without other additives, further simplifying the operations of preparation of the moulding mixture.
  • the binder premixed with the material according to the invention can be made available in two different concentrations, respectively with a percentage of 40-50% and 5-10% by weight of the above-mentioned material, according to whether it is to be used as a supplier of lustrous carbon or only to improve the workability of the sand.
  • the material according to the present invention can be supplied to the foundries in a liquid form, in drums or in bulk of 20 t, or, in a solid form, previously adsorbed in the above said proportions with the binder, for example bentonite, which can also contain other additives and conditioners of common use according to the needs of the foundries utilizing them.
  • the binder for example bentonite, which can also contain other additives and conditioners of common use according to the needs of the foundries utilizing them.
  • a moulding sand containing the material described in the present invention to be utilized in foundries of cast iron or non ferrous alloys such as bronze, brass and aluminum, for castings of medium thickness, can have the following composition:
  • a mixture of fatty acids and glycerides of fatty acids is used, obtained as a by-product of industrial processing and having a composition and chemo-physical characteristics equal to those set forth in the previous tables.
  • This moulding sand once in cycle, can be made-up with 1.1% of new sand, if the castings have few cores and their sand does not go in the moulding sand, with 0.3-0.4% bentonite in relation to the thickness of the castings produced and with 0.05-0.1% lustrous carbon supplying material.
  • the lustrous carbon supplying material is provided to the foundry in the form of a premix with bentonite, containing 40-50% of the former and 50-60% of the latter, the composition of the moulding sand, for the same type of iron castings will be:
  • composition For larger castings, whose nature implies high and wide vertical walls, the composition can be:
  • the make-up quantities considering the weight of the castings, can be increased slightly, in order to maintain the same technological properties of the sand. That is, bentonite can reach 0.4-0.45, and the lustrous carbon supplying material can be added in an amount of 0.1%; if however a premix of lustrous carbon supplying material and bentonite is used, the above additions are proportionately changed.
  • the Shatter index as a function of the humidity was measured. As shown in figure 2, diagrams a) and b), the Shatter index is greater for sample B containing the material according to the invention (figure 2%). For instance, samples containing 3% humidity have a Shatter index equal to 65 and 83 respectively.
  • the Shatter index is a parameter which is directly proportional to the mouldability of the sand.
  • the material according to the present invention can be made by mixing mostly unsaturated fatty acids and triglycerides of the same fatty acids in a proportion to reach a minimum content of fatty acids of no less than 40%, or by-products of industrial processing containing said substances and suitable for use in casting can be used.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Mold Materials And Core Materials (AREA)
EP92830679A 1991-12-24 1992-12-18 Nassgusssand enthaltend Fettsäure und Triglyceride Withdrawn EP0549547A1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
ITFI910309A IT1252822B (it) 1991-12-24 1991-12-24 Additivo per migliorare la scorrevolezza e la plasticita' di terre di formatura a verde
ITFI91309 1991-12-24
ITFI920101A IT1262904B (it) 1992-05-05 1992-05-05 Materiale fornitore di carbonio brillante a basso potere inquinante per terre di formatura a verde.
ITFI92101 1992-05-05

Publications (1)

Publication Number Publication Date
EP0549547A1 true EP0549547A1 (de) 1993-06-30

Family

ID=26330501

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92830679A Withdrawn EP0549547A1 (de) 1991-12-24 1992-12-18 Nassgusssand enthaltend Fettsäure und Triglyceride

Country Status (1)

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EP (1) EP0549547A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2771663A1 (fr) * 1997-12-03 1999-06-04 Manfred Buchler Composition fluide capable de produire du carbone brillant au cours de la coulee du metal et son procede de preparation
US20220041517A1 (en) * 2018-09-28 2022-02-10 Imerys Usa, Inc. Production of foundry premix composition

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2272483A (en) * 1938-02-23 1942-02-10 Armour & Co Core oil
CH273466A (de) * 1948-12-23 1951-02-15 Oel Und Chemie Werk Ag Kernöl für Giessereizwecke.
SU490553A1 (ru) * 1974-03-04 1975-11-05 Смесь дл изготовлени литейных форм
SU827241A1 (ru) * 1978-03-31 1981-05-07 Предприятие П/Я Р-6543 Разделительное покрытие дл модельнойОСНАСТКи
SU1569331A1 (ru) * 1988-03-02 1990-06-07 Дагестанский Политехнический Институт Способ подготовки керамической массы дл изготовлени стеновых изделий

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2272483A (en) * 1938-02-23 1942-02-10 Armour & Co Core oil
CH273466A (de) * 1948-12-23 1951-02-15 Oel Und Chemie Werk Ag Kernöl für Giessereizwecke.
SU490553A1 (ru) * 1974-03-04 1975-11-05 Смесь дл изготовлени литейных форм
SU827241A1 (ru) * 1978-03-31 1981-05-07 Предприятие П/Я Р-6543 Разделительное покрытие дл модельнойОСНАСТКи
SU1569331A1 (ru) * 1988-03-02 1990-06-07 Дагестанский Политехнический Институт Способ подготовки керамической массы дл изготовлени стеновых изделий

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 7636, Derwent Publications Ltd., London, GB; AN 76-68187X [36] & SU-A-490 553 (BARYSHEVSKII) 13 February 1976 *
DATABASE WPIL Week 8208, Derwent Publications Ltd., London, GB; AN 82-15260E [08] & SU-A-827 241 (ISAEVA) 22 May 1981 *
DATABASE WPIL Week 9118, Derwent Publications Ltd., London, GB; AN 91-130762 [18] & SU-A-1 569 331 (DAGESTAN POLY) 7 June 1990 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2771663A1 (fr) * 1997-12-03 1999-06-04 Manfred Buchler Composition fluide capable de produire du carbone brillant au cours de la coulee du metal et son procede de preparation
WO1999028064A1 (fr) * 1997-12-03 1999-06-10 Huttenes Albertus France (S.A.R.L.) Composition fluide capable de produire du carbone brillant au cours de la coulee du metal et son procede de preparation
US6506817B1 (en) 1997-12-03 2003-01-14 Huttenes-Albertus France S.A.R.L. Fluid composition for forming lustrous carbon during metal casting and process for its preparation
US20220041517A1 (en) * 2018-09-28 2022-02-10 Imerys Usa, Inc. Production of foundry premix composition
US11780782B2 (en) * 2018-09-28 2023-10-10 Imerys Usa, Inc. Production of foundry premix composition

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