The sponge gold (99.92 % pure) has been leached with ammonium thiosulfate solution. In this investigation, the gold leaching rate (extraction rate) and the thiosulfate oxidation rate (consumption rate) have been studied on the effects of CuSO₄, (NH₄)₂S₂O₃, (NH₄)₂SO₄, NH₄OH, stirring speed and retention time. The copper ion acts as a catalyst in gold dissolution, on the other hand, it also accelerates oxidation of thiosulfate (consumption). It was found that the best gold extraction was obtained at 12 hours under following optimum conditions:0.8 ∼ 1.0 mol / l (NH₄)₂S₂O₃, 0.03 mol / l CuSO₄, 2.0 ∼ 3.0 mol / l NH₄OH, 0.4 ∼ 0.5 mol / l (NH₄)₂SO₄, pH 10 ± 0.2 and 150 rpm. The thiosulfate oxidation is about 15 % of the initial concentration.

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Many studies have been done with ammonium thiosulfate to reduce the time of fixing. But some difficulties prevent even now the general use of the rapid fixing, while the necessity grows more and more in the rapid processng of film in the cinematography, television and vanadium development.
Authors have collaborated in the fundamental studies of this subject. The time of fixing is reduced in less than one third of ordinary fixer. The optimum concentration is found in the range 15-20% with ammonium thiosulf ate, about the half of sodium thiosulfate. The rapid fixer of ammonium thiosulfate has more buffer action in pH of the solution.
Ammonium thiosulfate is susceptible to the decomposition by heat. PH of the solution should be kept in the range of 4.5-6.0 One of the recommended formula is:
water 300cc
ammonium thiosulfate (60%) 100cc
sodium sulfite anhydrous 5g
glacial acetic acid 1.5cc
boric acid 3.8g
potassium alum 7.5g
water to make 500cc
pH 4.60

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定着廃液の再生法について研究した結果,廃液中の銀量に対し,理論量の2～4倍程度の多硫化アンモニウムを沈殿剤とし,pH4～7の弱酸性領域において,硫化銀沈殿を生成せしめる時は,ロ別の容易な沈殿が得られ,銀の除去率も十分高く(96%以上になる),しかも沈殿ロ去後の残液は,遊離イオウに汚濁されることのない透明なものが得られる。沈殿はまた,沈降速度も極めて速かであるから,傾鴻によっても容易に分けることができる。
銀除去後の残液は,廃液にくらべ,定着能力は著しく回復するが,これに不足概算量の定着薬晶を補充して得られた再生液の定着能力は,新液と完全に同等で,かつ,定着作用に支障を認められなかった。
また,再生回数と定着薬品量の関係についても述べた。

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生物活性炭は, 生物分解阻害性物質および難分解性有機物を含有する廃水処理に有効な方法として注目されている。本研究では, 生物活性炭による写真廃液の処理特性について検討した。実験は, 好気性の生物膜固定床型リアクターを用い, 滞留時間24hで行った。全実験系で1週間以内にpH 3程度まで急速に低下した。これはイオウ酸化菌によってチオ硫酸塩が硫酸塩へ酸化されたためと考えられた。また, 多孔質セラミックを担体としたものとの比較実験から, 活性炭を担体とした方が同じ装置規模ではより早い生物馴致と, 高い処理効率を得ることが確認された。このことから, 活性炭の吸着現象が生物活性を高めていると推測された。さらに, 後段のpHを7にコントロールした二段処理システムについて検討し, COD減少量のうち63%がチオ硫酸塩の酸化によることが分かった。システム全体のCODおよびBODの除去率は83および99%と, 高い処理効率が得られた。

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For securing noble metal resources, recovery of noble metals from urban mines is a key technology. Recently, ammonium thiosulfate solution has attracted attention as a safe and low-cost solution for gold leaching. We previously reported a noble metal recovery process using electroless displacement deposition onto silicon powder. In this study, we tried to use silicon powder to recover gold from an ammonium thiosulfate leaching solution. For experimentation, we added silicon powder to a simulated ammonium thiosulfate leaching solution containing 1 mM（M: mol dm^－3）sodium gold（I）sulfite and copper（II）sulfate（oxidizing agent for gold dissolution）. In the cases that the copper（II）sulfate concentration was 5 mM or higher, gold was not recovered even after 24 h treatment. However, we recovered gold successfully in 3 h by decreasing the copper（II）sulfate concentration to 2 mM or less. We also recovered gold in 3 h by changing the pH from 10 to 13 of the solution containing 5 mM copper（II）sulfate.

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Rapid processing for positive films is described. Developing time is 10 sec. at 30°C in MQ developer of which pH value is brought higher by sodium hydroxide, fixing, 15 sec. at 35°C in dilute ammonium thiosulphate solution (1: 4); washing 8 sec. by water-spray system ; drying, 30 sec. by heated air and infra-red heating Finally, automatic rapid develping machine of positive films for slow motion TV use is described in shot. All processing takes about 60 sec.

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It has been well known that it is very difficult to develop and fix of oscillograph paper within about 10 seconds completly.
This paper describes on the research of rapid processing for oscillograph paper with an automatic rapid daylight processing machine. Two kinds of processing machines (cf., fig. 3, 4) for this purpose were made and tested.
Experimental processing formulae with these machines for cardio type oscillograph paper are f ollows:
Rapid developer; water 700 ml., Na₂SO₃ 45g, 1-phenyl-3-pyrazolidone 1.1g, metol 15g, hydroquinone 15g, NaOH 60g. and water to make 1000 ml. Developing time is 2 sec. at 20°C.
Rapid fixer;(NH₄) ₂S₂O₃ concentrated solution (Nissan Rapid Fixer) 200 ml. and water to make 1000 ml. Time of complete fixing takes about 60 sec. at 20°C.
But when some kinds of chlorobromide paper of other purposes are processed in the following solutions, time of processing is very shortened.
Rapid developer; water 700 ml., Na₂SO₃ 30g, 1-phenyl-3-pyrazolidone 0.9g, metol 15g, hydroquinone 15g, NaOH 60g. and water to make 1000 ml. Developing time is 2 sec. at 20°C.
Rapid fixer; same formula as for cardio type is utilized. Time of complete fixing is only 12 sec. at 20°C.
In this research, a chlorobromide paper with a thin emulsion layer was experimentally made, and its processing time was much more shortened as follows. Time of development is 2 sec., and time of complete fixing is only 5 sec. in above formulae.

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Results of the basic and practical studies on the ammonium thiosulf ate fixer were already reported by authors. As this fixer consists of ammonium salt instead of sodium salt in common hypo fixer, it may occur that explosive substances such as silver fulminate or silver azide can be formed in the electrolytic recovering process. So, tests for electrolysis of this fixing solution were carrid out, varying current densities at various pH values. Then the silver deposits and the precipitated substances from these solutions were tested of the impacts and the ignition-sensitivity and analysed the precipitated substances to examine the presence of silver azide. Moreover, the analysis of the electrolysed liquid were carried out. Neither trace of silver fulminate nor silver azide could be found in the solution. Impact- and ignition-test showed that the silver deposits and the precipitated substances did not contain the detonating substances. So, it may be conculuded that the electrolytic silver recovery from the waste rapid fixer can be done in safety.

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Rayon fabrics, untreated or treated with sulfur-containing acids, nitrogen-containing bases and their salts or mixtures, were pyrolysed at 300°C in air, and the yields and the tensile strengths of charred rayon fabrics were measured. For the comparison, the salts of phosphoric acid, hydrochloric acid or nitric acid were also examined as treating agents.
All of the compounds investigated, except ammonium nitrate, act to increase yield of charred fabrics. On the other hand, the compounds remarkably increasing tensile strength of charred fabrics seem to be restricted to the combinations of following acids and bases; Acid: surfuric acid, sulfurous acid, sulfamic acid and thiosulfuric acid Base: ammonia, urea, guanidine triethanolamine and aniline
The results are discussed in relation to the flameproofing mechanisms of cellulose.

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