Study of the impact of phosphogypsum additive and ferrous sulphate solution on the mechanism of the magnesia-bishofit composition

V. N. Derevianko, A. A. Maksimenko, H. M. Hryshko

Abstract


Problem statement. Phosphogypsum is a very pure raw material [16] with a negative, from a technical point of view, elongated shape of calcium dihydrate crystals (due to the formation conditions), which remains the same after both dehydration in dry air and grinding, this makes technical difficulties relating to further processing of the product into a binder, consequently, water resistance and plasticity of magnesium solutions can be improved by adding primary and secondary phosphates without strength reduction. Famous experts on phosphogypsum Yu. P. Meshcheryakov and N. A. Kolev [8] found, that when adding phosphogypsum instead of natural gypsum during grinding of Portland cement, which is intended to control the setting time of the mixture, there occurred reduction in the initial setting time from 1 h 55 min up to 1 h 36 min (when adding 4 % agent), and the final setting time was decreased from 6 h 15 min up to 6 min. After grinding of phosphogypsum, there appeared a fresh surface, on which the electron emission phenomenon occurs, however, not the entire surface emits, but only the active centres, where field strength reaches 108 V/cm. The positively charged active centres have low CaSO4 2H2O concentration on their surface.

Purpose. Specifying the optimal amount of phosphogypsum and ferrous sulphate solution added, studying their impact on the curing mechanism of the magnesia-bishofit composition.

Conclusion. To increase the sulphate compound, required for the crystallinity [10] reduction and magnesia stone sealing [4], the ferrous sulphate solution have been added to the composition formulation, ferrous sulphate anions immediately polarize free calcium ions with the formation of CaSO4∙2H2O. P. P. Budkov's experiments [8] prove that the larger the magnesia cement-to-sulphate stone ratio, the lower the setting time of the composition, and the higher the tensile strength of the stone. Moreover, V. V. Shchelyaghin [15] recommended adding ferrous sulphate, formed in tanks for black metal etching with sulphuric acid, to the magnesia-bishofit composition. The scholar replaced up to 50 % of the magnesium chloride solution MgCl2 for the ferrous sulphate solution FeSО4·7H2О, thus improving water resistance of the stone. He also established that ferrous sulphate accelerates setting time of magnesia mixtures and reduces the chance of efflorescence formation on the product. Therefore, based on the results of the research conducted, 5 % of phosphogypsum is the optimal amount to be added to the magnesia-bishofit composition. The additive reduces the setting time of the mixture and increases the strength of the stone, and together with the 5 % ferrous sulphate additive it enables formation of a sealing newgrowth CaSO4 2H2O. Clogging of pores with dehydrite particles and bonding flakes of Fe(OH)3 improves deformation phenomena during curing of the specimens, reduces their water absorption capacity and increases strength.


Keywords


curing; additive; magnesia-bishofit composition; phosphogypsum; ferrous sulphate; setting time; water demand; mixing

References


Bozhenov P.I. Tehnologija avtoklavnyh materialov [Technology of autoclave materials]. Leningrad: Strojizdat, 1978, pp. 30-35. (in Russian).

Butt Ju.N., Volkonskyj B.V., Egorov G.B., Korneev V., Nikiforov Ju.V., Svatovskaya L.B., Sudakas L.B., Sychov M.M. and Timashev V.V. Spravochnik po himii cementa [Manuel of chemistry cement]. Leningrad: Strojizdat, 1980, 187 p. (in Russian).

Vojvad A.Ju. Magnezial'nye vjazhushhie veshhestva [Magnesia cement]. Riga: Znanie, 1971, 331 p.

Vojtovich V.A. and Spirin G.V. Poly na osnove magnezial'nyh vjazhushhih veshhestv [The floor on the basis of magnesia cement]. Stroitel'nye materialy [Building materials]. 2003, no. 9, pp. 8-9. (in Russian).

Golynko-Vil'fson S.L., Sychev M.M., Sudakas L.G. and Skoblo L.I. Himicheskie osnovy tehnologii i primenenija fosfatnyh svjazok i pokrytij [The chemical basis of technology and useage of phosphat binders and bonderites]. Leningrad: Himija, 1968, p. 95. (in Russian).

Kaminkas A.Ju. Novoe v tehnologii izgotovlenija silikatnyh izdelij s primeneniem magnijsoderzhashhih vjazhushhih: obzor [New in the technology of manufacture of silicate products using magniferous binding material: overview]. Moskva: VNIIJeSM, 1978, 60 p. (in Russian).

Krasil'nikov K.G., Nikitina L.V. and Skoblinskaya N.N. Fiziko-himija sobstvennyh deformacij cementnogo kamnja [physico-chemistry of its own deformation of cement rock]. Moskva: Strojizdat, 1980, p. 255. (in Russian).

Meshherjakov Ju.G. and Fedorov S.V. Jenergosberegajushhie tehnologii pererabotki fosfogipsa i fosfor-polugidrata [Energy-saving technology of recycling of phosphogipsum and phosphohemihydrat]. Stroitel'nye materialy [Build- ing materials]. 2005, no. 11, pp. 56-57. (in Russian).

Pirogov Ju.A. and Fishherova A.I. Fosfatnoe svjazyvanie periklaza [Phosphate binding of periclase]. Ogneupory [Refractories]. 1969, no. 11, pp. 44-47. (in Russian).

Plehanova T.A. Magnezial'nye kompozicionnye materialy, modificirovannye sul'fatnymi dobavkami: avtoref. dis. na soisk. uch. stepeni kand. tehn. nauk: 05.23.05 [Magnesium composite materials modified sulfate supplements: Ab- stract of Ph. D. Dissertation]. Kazan', 2005, 22 p. (in Russian).

Pozin M.E., Kopylov B.A. and Talmud M.M. Novoobrazovanija v magnijnofosfatnom kamne [Newgrowths in magnesium phosphat rock]. Zhilishhno-kommunal'noe hozjajstvo [Housing and utilities infrastructure].1965, no. 6, pp. 97-103. (in Russian).

Poling L. Obshhaja himija [General chemistry]. Moskva: Mir, 1974, 345 p. (in Russian).

Ratinov V.B. and Rozenberg T.I. Dobavki v beton [Аdmixture to the concrete]. 2th edition. Moskva: Strojizdat, 1989, 188 p. (in Russian).

Sychev M.M. Problemy razvitija issledovanij po gidratacii i tverdeniju [Problems of research development by hy- dration and hardening of cement]. Cement [Cement]. 1989, no. 1, p. 26. (in Russian).

Shheljagin V.V. Magnezial'nyj cement. Syr'e, tehnologija poluchenija i svojstva [Magnesia cement. Raw materials, technology of production and properties]. Moskva: Gostrojizdat, 1933, 107 p. (in Russian).

Shul'ce V., Tishe V. and Jettel’ V. Rastvory i betony na ne cementnyh vjazhushhih [Mortars and concretes on the not cement binding]. Moskva: Strojizdat, 1990, p. 226. (in Russian).


GOST Style Citations


Боженов П. И. Технология автоклавных материалов / П. И. Боженов. – Ленинград : Стройиздат, 1978. – С. 30-35.

 

Справочник по химии цемента / Бутт Ю. М., Волконский Б. В., Егоров Г. Б., Корнеев В. И., Никифо- ров Ю. В., Сватовская Л. Б., Судакас Л. Г., Сычев М. М., Тимашев В. В. ; под ред. Б. В. Волконского, Л. Г. Судакаса. – Ленинград : Стройиздат, 1980. – 224 с.

 

Войвад А. Я. Магнезиальные вяжущие вещества / А. Я. Войвад. – Рига : Зинатне, 1971. – 331 с.

 

Войтович В. А. Полы на основе магнезиальных вяжущих веществ / В. А. Войтович, Г. В. Спирин // Строительные материалы. – 2003. – № 9. – С. 8-9.

 

Химические основы технологии и применения фосфатных связок и покрытий / С. Л. Голынко-Вильфсон, М. М. Сычев, Л. Г. Судакас, Л. И. Скобло. – Ленинград : Химия, 1968. – С. 95.

 

Каминкас А. Ю. Новое в технологии изготовления силикатных изделий с применением магнийсодержащих вяжущих : обзор / А. Ю. Каминкас. – Москва : ВНИИЭСМ, 1978. – 59 с.

 

Красильников К. Г. Физико-химия собственных деформаций цементного камня / К. Г. Красильников, Л. В. Никитина, Н. Н. Скоблинская. – Москва : Стройиздат, 1980. – 255 с.

 

Мещеряков Ю. Г. Энергосберегающие технологии переработки фосфогипса и фосфополугидрата / Ю. Г. Мещеряков, С. В. Федоров // Строительные материалы. – 2005. – № 11. – С. 56-57

 

Пирогов Ю. А. Фосфатные связывание периклаза / Ю. А. Пирогов, А. И. Фищерова // Огнеупоры. – 1969. – № 11. – С. 44-47.

 

Плеханова Т. А. Магнезиальные композиционные материалы, модифицированные сульфатными добавками : автореф. дис. на соиск. степени канд. техн. наук : спец. 05.23.05 “Строительные материалы и изделия” / Т. А. Плеханова. – Казань, 2005. – 22 с.

 

Позин M. E. Новообразования в магнийнофосфатном камне / M. E. Позин, Б. А. Копылов, М. М. Талмуд // Жилищно-коммунальное хозяйство. – 1965. – № 6. – С. 97-103.

 

Полинг Л. Общая химия / Л. Полинг ; пер. с англ. В. М. Сахарова. – Москва : Мир, 1974. – 846 с.

 

Ратинов В. Б. Добавки в бетон / В. Б. Ратинов, Т. И. Розенберг. – 2-е изд., перераб. и доп. – Москва : Строй- издат, 1989. – 188 с.

 

Сычев М. М. Проблемы развития исследований по гидратации и твердению цементов / М. М. Сычев // Цемент. – 1989. – № 1. – С. 26.

 

Щелягин В. В. Магнезиальный цемент. Сырье, технология получения и свойства / В. В. Шелягин. – Москва : Гостройиздат, 1933. – 62 с.

 

Шульце В. Растворы и бетоны на нецементных вяжущих / В. Шульце, В. Тише, В. П. Эттель ; пер. с нем. Т. Н. Олесова. – Москва : Стройиздат, 1990. – С. 226.



Refbacks

  • There are currently no refbacks.