Effect of modifying additions on the binding properties of lignosulfonates

The effect of various modifying additions to technical lignosulfonates used in the production of periclase (from fused and sintered periclase), chromite-periclase, and thermostable chromite-periclase articles is investigated. An acceptable strength for the green material for periclase articles is provided by lignosulfonates produced by the Kamsk Wood-Pulp and Paper Plant. The recommended modifying addition is carbamide. An addition of tall oil reduces the strength of greenware but improves the properties of articles after firing. Lignosulfonates with additions of carbamide, aluminum chloride, and titanium sulfate are considered the most efficient for chromium-containing articles.Translated from Ogneupory, No. 12, pp. 15 – 21, December, 1994.     

Isolation of lactic whey proteins in the form of complexes with apple pectin

The possibility of isolating lactic whey proteins (LWP) in the form of insoluble complexes (IC) with apple pectin was studied. The effect of pH, ionic strength (mu, NaCl), temperature (T degree C), pectin weight fraction (X3%) and the total concentration of macromolecular components in the system (Ws) on isolation has been considered. The process has been characterized by LWP yield in the composition IC--P, percentage and the extent of protein concentration in the concentrated phase (IC)--F. The mixing of lactic whey with a pectin solution usually yielded an IC (10% less than or equal to X3 less than or equal to 90%). The dependence of P on X3 is of an extreme nature with a maximum of 85% at X3 = 60%. The following conditions correspond to the maximum LWP yield (90%) in the complex composition: pH 3.4, mu = 0.01, T = 5-20 degrees C, X3 = 60%, Ws = 0.5%. At compositions of the system corresponding to the maximum P value (X3 = 60%) practically all the LWP fractions are present in the concentrated phase. If X3 much greater than 60% or X3 much less than 60% alpha-lactalbumin is practically absent in the concentrated phase. Usually, minimum F values (2.5-4.0) correspond to maximum protein yield at X3 = 60%. At X3 greater than 70% and X3 less than 50% F values may be considerably higher (20 times and more). A decrease in the pectin methylation degree from 56.7% down to 15.4% does not affect F. The maximum protein yield (94%) occurs when low methylated pectin is used. The character of the dependence of F on X3 is explained according to similar processes of complex gel formation and the processes of gel formation in polymer solutions.     

Structural group composition of sulfonate additives

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 9, pp. 34–35, September, 1990.     

Young scientists' conference

Refractories and Industrial Ceramics -     

New method of determining the slag-resistance of refractories

Conclusions A new method is proposed for determining the slag resistance of refractories with lever apparatus which is qualitative.The new technique permits the specific features of the destruction of refractories by slags to be determined, and explains the mechanism of this process by mineralogical analysis and by describing the external appearance of the changed specimens.Data on the changes in the specimens during tests and the compositions of the zones will be given in the next article.Data obtained by the new method show that the slag destruction of refractories accelerates with time.     

Strength after heating of unfired refractories containing chemical bonding agents

Conclusions Out of all the experimental bonding agents used in the production of unfired magnesite and magnesite-chromite refractories: SDW; MgSO₄,· 7H₂O; MgSO₄·7H₂O + H₃BO₃; (NaPO₃)_n, the greatest strength on heating is provided by the addition of 2% (NaPO₃)_n.An addition of boric acid to the refractories using the MgSO₄,·7H₂O bonding agent helps to strengthen the refractories in the 500–900°C interval; at a higher temperature the refractories with the magnesium sulfate plus boric acid bonding have no advantages in their strength properties over the articles with the magnesium sulfate bonding agent only.The magnesite-chromite articles with the chemical bonding agent have better strength in the 1000–1400°C interval than the magnesite articles. This is explained by the spinelformation reactions which occur at these temperatures.On the basis of these studies (NaPO₃)_n and also MgSO₄,· 7H₂O with an addition of H₃BO₃ can be recommended as chemical bonding agents for unfired magnesite-chromite refractories.Translated from Ogneupory, No. 1, pp. 48–52, January, 1979.     

Test complex for the onboard navigation system of an airport ground vehicle

An experimental model of the onboard integrated navigation system for airport ground vehicles designed for use as part of an advanced surface movement guidance and control system is considered. The technique and the results of field tests of the system are presented. The composition and design of the mobile test stand are described.