Pulp Solution Research Articles

Viscometric determination of molecular weight of cellulose pulps in zinc ethylenediamine solution

A convenient method of preparing zinc ethylenediamine complex (ZED) solution for use as solvent for cellulose pulp is described, and the advantages in using this solvent (0.25M zinc in 41% ethylenediamine in water) over cupriethylenediamine (CED) or cuprammonium solutions for viscometric determination of molecular weight of cellulose are indicated. Intrinsic viscosities of eight rayon-grade pulp solutions have been determined at four temperatures: 15, 20, 25, and 30°C. The constants K = 5.85 × 10−5 and a = 0.936 of the Mark-Houwink equation [η] = KM, required for evaluating the molecular weight of cellulose pulps in ZED solution, have been determined by using the molecular weight values obtained from CED solutions.

A Simple Technique for the Evaluation of Slime Control Agents

A laboratory procedure for the realistic screening of paper mill toxicants is described.This method is modified for the pulp substrate method that was already proposed by Appling et al in 1951. The technique consists of two parts, that is ;The technique I is using 1% of pulp solution for the test culture substrate, and Pseudomonas melogenes, Penicillium steckii, Aspergillus niger and Humicola grisea are inoculated on it for the test organisms.The technique II is employed as slime sample which was taken directly from an area of the mill system in stead of the test organisms. The dilution plate method is made for an evaluation of biosides mixing substrates in which slime forming organisms had been growing.This technique is available for the selection of slime control agents at the laboratory of paper mills.

A Simple Method for the Measurement of the Concentration of Pulp Solution

A Simple Method for the Measurement of the Concentration of Pulp Solution

Recent progress in flotation

ONE of the most marked and revolutionary advances of recent years in the art of concentrating ores is the advent and application of the flotation process. Although the basic and essential principles of flotation had been disclosed by the early work of Haynes, Everson, and the Elmore brothers, it is only within the last decade or so that the process has been a commercial success. Historical considerations point out the fact that the installation of the Delprat process, in 19o3, at the Broken Hill Proprietary mine in Australia, was probably the first important commercial application of any flotation process; some other installations were also made at or about the same time. Flotation as practised to-day is the result of the diligent labor of many men, and the present state of development cannot lye ascribed to any one individual. In its early stages the flotation process of concentration was decidedly uncertain of success because of certain inherent difficulties which were to be overcome. At present every mill owner in the country is considering its applications. The froth flotation process is markedly efficacious in extracting the mineral sulfides from slimes, and, in the main, is more or less restricted to the treatment of extremely fine material. In a general way, there are three divisions into which the flotation processes may be separated; namely, ( I ) film flotation, (2) bulk-oil flotation, and (3) froth flotation. Further, these three classes blend into one another gradually, according to the patents secured for the different processes. Technical distinctions are based on such points as these, viz., acid, neutral, or alkaline pulp solutions ; mill temperature or hot solutions ; various secondary apparatus employed for the introduction of air or the production of gas bubbles; amounts of oil; and other minor differences almost ad int~nitum. The more important processes which