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The present paper gives recommendations for developing researches oriented to improve prediction of solids concentration in sludge obtained by gravitational sedimentation. In thickener plant of PSA- Moa Nickel S.A. Company this prediction is studied by means of the historical, logical and passive experimentation methods. It is concluded that in order to solve the problem concerning the prediction of the solids concentration in sludge obtained by gravitational sedimentation, it is advisable to focus the research to the theoretical and empiric study of statistical correlation between this variable and the solids concentration obtained by others mechanical separation methods. [ABSTRACT FROM AUTHOR]

The acid leaching pressure technology used in cuban nickel hydrometallurgical industry do not reach the mass concentration settled down by design (48 %) at the end of the thickening process, so national economy is affected. By means of X-ray diffraction analysis (XRD) mineralogical phases were determined in the mineral ore. With the sedimentation essays the behaviour of them was studied in the lateritic pulps. It is concluded that the presence of heavy metals phases (hematite, loadstone and maghemite) in the pulp, favors the sedimentation process, whereas the presence of light metals phases as gibbsite, quartz, antigorite and hematite produces the opposite effect. [ABSTRACT FROM AUTHOR]

This paper describes some results of a study carried out on the stability of Diesel -- Fuel Oil blends. The stability is evaluated by macroscopic properties such as viscosity and density. The effect of tensioactive agents on these mixtures was also studied. The stratification of mixtures was followed during storage. It is also analyzed the contribution of asphaltenes in blends stability. [ABSTRACT FROM AUTHOR]

In the work a preliminary study about waste liquor (WL) treatment of the lateritic ore high pressure acid leaching is presented. The WL neutralization using tails of the ammoniacal carbonate leaching process and later liquid separation with membranes, makes possible to recuperate water for industrial process and return reject containing Ni + Co to sulphur precipitation plant. Taking as basis a 100 m³/h osmosis inverse installation for water treatment, and considering selection and calculus methods in the consulted bibliography, the required membranes area for the neutralized liquor treatment was determined. A valuation cost for an industrial membrane plant and probable investment recuperation time is also determined. [ABSTRACT FROM AUTHOR]

To be able to carry out the determinations of the percent of apparent sucrose in juice by the polarimetric method, it is indispensable the clarification of the samples. For the clarification the load acetate has been substituted by the aluminium chloride, which requires of a relatively high dose (4g/L). With the objective of diminishing the reagent dose to be applied, in this work are employed seven flocculants produced and marketed by the signature CIBA. The analysis were carried out in juices of the variety C87-51 to which it was determined the equal electric point. It was carried out the determination of the percent of apparent sucrose in juice, and they were compared the obtained values when it was used the aluminium chloride and each one of the seven flocculants. It was proven that the equal electric point of the juice of the C87-51 is of 6,69 units of pH. When adding the aluminium chloride so as five of the used flocculants, it was achieved the clarification of the juice, what allowed to carry out the polarimetric reading, being concluded that the substitution of the aluminium chloride for the flocculants PERCOL LT-24. PERCOL E-10, DRIMAX 12 358, PERCOL LT-20 and MAGNEFLOC LT-27 is feasible, when reducing in five times the dose to be applied. It was also demonstrated that the compounds that achieve a more complete clarification of the juice are the flocculants DRIMAX 12 358, PERCOL E-10, PERCOL LT-20, MAGNEFLOC LT-27. It is recommended to continue these studies to determine the dose and the good type of agitation for the cane juice. [ABSTRACT FROM AUTHOR]

A study to establish CIBA flocculant effects in the liquid waste treatment of the Milky Factory of Santiago de Cuba was carried out, to diminish the pollution charge in San Juan river. It was characterized that the waste one is a polydisperse system of organic and inorganic composition, highly polluting and aggressive, whose particles are considered liophylic. For its treatment were assayed seven flocculants, resulting the most efficient the cationic flocculant PERCOL LT-22 in 4 mg/L dose, submitting the waste to a mixture in an agitator with an agitation velocity of 620 r/min during 100-205 sec. [ABSTRACT FROM AUTHOR]

This paper includes results of the research works on the direct (O/W) emulsion preparations of the Cuban crude petroleum, using pyrolysis products as emulsifier agent. Rheological characterization of the emulsions, immediately after their preparation and inside of some storage time is informed, so as some considerations about piping transport of these emulsions are reported. [ABSTRACT FROM AUTHOR]

In the paper, a study about the use of possibilities of a new type emulsifyng agent obtained from pyrolyisis products of lignocellulosic materials, with Cuban crude petroleum for the preparation of emulsioned paints is presented. The viscosity reduction, the improvement in the handling and the use of obtained emulsions as substitute of asphaltic paints are informed. It is proved that may be obtained direct emulsions with Cuban crude petroleum concentrations of 50-60 % wt., using 3 % wt. concentration of emulgent P (here it is called emulsifyng agent) respect to water. The emulsion characteristics are mantain similar to others prepared with tensioactive agents commonly used. [ABSTRACT FROM AUTHOR]

The classification of very fine particles by the conventional methods is very difficult, due to the present superficial-interaction forces which provoke conglomeration. This phenomenon is avoided by the hydroneumatic classification. This work shows different experiences which prove the factibility of it. It was demonstrated that the flow of water is the most important variable of the process, but it is necessary to pay attention to the bubbles of air which give some impulse to the particles and provoke the decrease of the area of flow. It was proved that the classificated particles of a mix of substances are isodroms and that the 80 % of the classificated material was collected in the first 30 min. [ABSTRACT FROM AUTHOR]

In this work are presented the results obtained in the first stage of the study made with the purpose of deepening in the knowledge of SAA behaviour, as a frother additive in the flotation process of copper sulfurized minerals, for which it was designed and built a flotation microcell, and it was confirmed the hidrodynamic functioning of it. Through the study made at this scale, it was confirmed the adequate hidrodynamic functioning of the microcell, and it was verified the SAA behaviour in the established conditions, constituting it a first step towards the search for the most favourable conditions of operation. [ABSTRACT FROM AUTHOR]