Froth Product Research Articles

A Wastewater Treatment System Applying Aeration-Cavitation Flotation Mechanism

Abstract A new type of wastewater treatment system applying not only aeration but also the cavitation flotation mechanism is proposed to attain high capacity and low operation cost. The system can be operated continuously in a single or multistage with ease. The system is composed of four isolated sections: feed section, aeration section, multiphase flow section, and separation section. Aeration and gas dissolution are carried out in the aeration section. Then collisions between the elements to be removed and gas bubbles, and cavitation of dissolved gas are accomplished in the multiphase flow section, followed by the recovery of the aggregates as the froth product in the separation section. The function of each section is evaluated by taking into consideration the contribution to the separation characteristics. It is confirmed through a series of treatment tests that the separation rate is a few tens of times faster than those in conventional treatment systems and, hence, lower energy consumption is anticipated in the proposed system.

Certain properties of three-phase flotation froths formed during the coal flotation process

Results are presented of studies on the mutual volumetric ratios of solid, liquid and gaseous phases in the three-phase froths formed during the coal flotation process. It was shown that these ratios are significantly dependent on the concentration of solid phase in the floated coal slurries suspensions, the coal rank, the composition of the flotation agent and in particular the volume of promoter it contains. These variables also influence that important technological parameter, content of solid parts in the froth product suspension. The relations ascertained were corroborated by the results of industrial trials.

Foaming in Pachycondyla: A new defense mechanism in ants

When disturbed, two species of Malayan Pachycondyla release foam threads more than 10 cm in length or foam piles. The source of the proteinaceous foam is the enlarged venom gland, which is probably frothed up by air from the spiracles of the spiracular plates. The Dufour's gland normally producing hydrocarbons in stinging ants is atrophied. Therefore, absence of the Dufour's gland could be essential to the foaming ability, since the lipophilic hydrocarbons inhibit froth production in protein solutions. The release of foam is a mechanically acting defense mechanism, which is very effective against small mass-attacking ants. Pachycondyla species are also able to sting effectively.

Bloat in cattle. XVI. Development and application of techniques for selecting drugs to prevent feedlot bloat.

THE prevention of bloat has been the object of many studies, the majority involving use of surface-active agents or antibiotics. Because feedlot bloat is essentially the frothy type (Meyer and Bartley, 1971), the introduction of synthetic detergents provided an abundance of surfactants that could be tested for froth inhibition in the rumen. However, to test in vivo the multitude of drugs available would be a prohibitive task. This paper describes a three-step program for screening drugs for prevention of feedlot bloat. The first step (Experiment 1) determines the effect of the drug on in vitro froth production, surface tension, relative viscosity, and microbial activity. In this step, 235 drugs were tested. The second step (Experiment 2) consists of administering potential bloat preventives to rumen-fistulated cattle fed a feed-lot bloat-provoking ration. The effect of 54 drugs on in vivo rumen froth production was evaluated. The last step (Experiment 3) in testing the efficacy of a bloat prophylactic was to administer the drug as a feed additive to cattle bloating on an all-concentrate ration.

浮選速度の異なる黄鉄鉱粒子の構造上の特性について

The previous reports showed that the flotation rate constant and ζ-potential were dependent on the value of atomic ratio S/Fe, crystallographic factors and the distribution of etching structures of pyrite. Notably in this connection, inverse relationship was observed under acid and alkaline conditions.In the present report, froth products taken from different flotation time intervals and the final tailing were analysed by chemical, spectroscopic and X-ray diffraction techniques and by scanning-type electron microscope, from the following points of view.1. to confirm the tendencies obtained in the previous works.2. to probe the inner structure and its properties of microscopic etching structures.It was proved from the results thus obtained that the structure and the stability of the surface corresponded to the respective flotation rates of the particle groups. Especially “agglomeration structure” was often found on the surfaces of particles whose flotation behavior can hardly regulated well in the flotation process.

Effects of CuSO4, Na2S, and water glass on flotation of sulfides from crude tin concentrate of the Khrustal'nen combine

1. It has been found that copper sulfate is not an activator of sulfides in the case examined in this paper. This is evidently due to the fact that a very slight concentration of copper sulfare, which induces activation, is present in the tin concentrate itself, so that addition of copper sulfate leads to an excess concentration of copper ions, thus depressing the sulfide minerals. 2. Water glass does not reduce the tin content of sulfides, extraction of the latter into the froth product being greatly reduced. 3. Small amounts of Na2S (50 g/ton) depress sulfide minerals.

Flotation of sulfides from the intermediate tin concentrate of the khrustal'nyi combine by xanthates of different composition and anp cation reagent

The flotation of sulfides from gravity tin concentrates leads to removal of minerals containing arsenic, bismuth, ant imony, copper, lead, and zinc, and also a large part of the sulfur and iron. The main problem in f lotat ion in this connection is more comple te removal of harmful impuri t ies and min imum losses of tin in the froth product. Xanthates are used for flotation in nearly a l l benef ic ia t ion plants handling sulfide ores. They exhibit col lec t ing properties for far fewer minerals than a l iphat ic acids, but have higher se lec t iv i t ies than the la t te r . Xanthates are salts of ac id esters of di thiocarbonic ac id .

Mode of Action of Penicillin in the Prevention of Uncomplicated Legume Bloat1,2

Summary The study was conducted to determine whether increased intraruminal stable froth formation is clearly associated with an increased incidence of naturally occurring bloat and how penicillin is effective in preventing bloat and why its preventive effect is short-lived. Fistulated and nonfistulated dairy animals were grazed and stall-fed under carefully controlled conditions on bloat-producing and nonbloat-producing alfalfa during 1960 and 1961. A number of stall-fed animals received penicillin or served as controls. Over an entire bloat season, stable froth formation in the rumen was found to be significantly correlated with the bloat index ( r = 0.42). The coefficient of correlation between bloat incidence and gas production by the rumen microorganisms (as determined by a Warburg apparatus) was highly significant (0.65), showing that an unusually high rate of gas production is involved in the etiology of bloat. The administration of penicillin significantly lowered both stable froth production and gas production. It was concluded that penicillin exerts its shortlived bloat preventive effect by decreasing the rate of stable froth formation in the rumen through a reduction in the rate of fermentation.