Method for protecting environment from volatile liquid chloride as exposed to the atmosphere

A method for protecting environment from volatile liquid chloride as exposed to the atmosphere, which comprises: PA1 spreading foamy particulates of styrene resin over the chloride, PA1 initiating a reaction between the resin and chloride at the interface to form a filmy product, and PA1 covering the surface of the chloride to a substantial part with a layer comprising such product, thus blocking evaporation of the chloride to spread and contact with humidity in the atmosphere.

The present invention relates to a method for protecting environment from 
volatile liquid chloride of metal, such as titanium tetrachloride or 
silicon tetrachloride, as accidentally exposed to the atmospheric air. 
Among liquid chemicals utilized widely in current chemical and 
metallurgical industries, there are a lot of materials such as titanium 
tetrachloride and silicon tetrachloride which, as exposed to the 
atmosphere, are very harmful to human health, by evaporating to spread the 
chloride which in itself is corrosive and poisonous and, in addition, 
yields a more poisonous chemical, hydrochloric acid vapor, when it 
contacts to react with humidity (water) in the atmospheric air. Therefore, 
such chlorides must be handled with the greatest care available not to 
spill into the atmosphere, and any portion accidentally exposed to the air 
by spilling or otherwise, should be quickly halted and blocked against its 
contact with the atmosphere. 
In case of such exposure, slaked lime is conventionally spreaded to cover 
the chloride on the surface so that the chloride may be neutralized and, 
at the same time, blocked from contact with the atmosphere. Since the 
lime, used as powder, only achieves rather a poor blockade from the air, 
while exhibiting a high density, a relatively thick layer, thus a large 
weight, of such material is necessarily moved to use with troubles before 
the chloride becomes harmless. Further the treatment has other drawbacks 
that with a chemical reaction with lime involved to a substantial part, 
the chloride cannot be recovered as an effective material, and that a 
thick dust rises when the lime powder is poured, so the fighters can 
hardly proceed with the work. 
Therefore, the principal objective of the present invention is to provide a 
method, substantially eliminated of such drawbacks, for protecting 
environment in case of an accidental exposure of the chlorides. 
The Inventor has found and based his invention on that the chloride such as 
titanium tetrachloride or silicon tetrachloride reacts with some kinds of 
resinous foam to efficiently polymerize, leaving a jellied layer of 
polymer at the interface so that an effective isolation is achieved 
between the chloride and atmosphere, and such filmy product is formed in 
an accelerated manner when any heat is supplied by reaction of chloride 
with atmospheric water to yield hydrochloric acid. 
According to the invention there is essentially provided a method for 
protecting environment from volatile chloride liquid as exposed to the 
atmosphere, which comprises: spreading foamy particulates of styrene resin 
over the chloride, initiating a reaction between the resin and chloride at 
the interface to form a filmy product, and covering the surface of the 
chloride to a substantial part with a layer comprising such product, thus 
blocking evaporation of the chloride to spread and contact with humidity 
in the atmosphere. 
The foamy particulates of resin, used in the invention as fume suppressive, 
essentially consist of styrene. Such tiny balls, each, may exhibit various 
sizes and apparent density: typically they are formed spheroidal having a 
diameter of about 3.about.4 mm and show a density of 0.02 to 0.014 g/cc. 
Obviously, the fume suppressive particulates of the invention are also 
applicable to other liquid chemicals, as far as a similar layer is formed 
at the interface by polymerization. 
The particulates may be stocked in various ways for provision against 
exposure of the chlorides in case of spilling or partial cracking of 
containers. For example, they can be stocked in a readily accessible bag 
or other containers provided close to chloride equipments, so that 
fighters readily can reach and pour them manually on the surface of 
exposed chloride; when the equipments are placed in a diked enclosure the 
particulates may be laid close to the ground in the area as uncovered or 
as put in a bag or like of a material readily breakable to open when in 
contact with the chloride so that the particulates when the chloride 
reaches may float and automatically spread over the surface; or they may 
be held in a stationary container-feeder which is placed close to the area 
and can be readily controlled manually from a remote place, or even 
automatically. Such provisions can be employed either singly or in 
combination with each other. 
Since the layer at the interface in itself is water repellant and promoted 
to form by heat supplied by reaction of the chloride with water to reach, 
once such layer has been formed to cover the chloride to a substantial 
part, penetration of any water to reach the chloride will not cause any 
more fuming of the chloride itself or yielded hydrochloric acid. 
In the invention environmental protection by fume suppression is best 
achieved when the layer as a whole consists of a jellied film; a close 
result can be obtained when the layer to a part comprises partly consumed 
or unconsumed particulates joined with adjacent ones and with the film, as 
the still air trapped in such particulates serves as an insulator. 
Reaction between the resin and chloride slows down after the jellied films 
form to intervene, so that the latter can be recoverd to a substantial 
part as an effective material after the fume has subsided. 
Since the particulates exhibit a by far lower density and thus dissolves in 
the liquid chloride to a very limited degree, the chloride can be 
recovered with a substantial improvement in both purification and volume 
to be scrapped.

EXAMPLE 1 
Liquid titanium tetrachloride was tentatively spreaded over an 
approximately one squared meter of area open to an atmosphere of a 
relative humidity of 70%. 500 grams of foamy particulates having a 
diameter of about 3.about.4 mm was manually poured on the chloride to 
cover substantially the entire surface. In about ten seconds after the 
pouring, the chloride was covered with a jellied layer, and fume evolved 
no more when water was poured onto the covered chloride. 
EXAMPLE 2 
A titanium tetrachloride tank was used which was placed in an enclosure 
wide 2 m by 2 m, with a 50 cm high dike on the periphery. Up inside the 
area a funnel bottomed container-feeder was equipped which was loaded with 
spheroidal particulates having a diameter of about 3.about.4 mm of styrene 
resin, and remote controllable. Immediately after some 20 liters of liquid 
titanium tetrachloride was tentatively spilled in the enclosure, the 
container-feeder was opened from a distant panel to pour about 8 kg of the 
styrene particulates to spread over all the area. In 30 seconds the 
chloride was entirely covered with a jellied film. Thus treated, the 
chloride did not evolve any fume when water was poured thereon, 16 liters 
of chloride as recovered was available as an effective material. 
As described above in detail, by utilizing as fume suppressive foamy 
particulates of a considerably lowered density and a high reactivity with 
the chlorides to yield a water or gas impermeable layer formed at the 
interface, the invention permits a substantially improved workability and 
security, so as to readily protect environment in any accidental exposure 
of the chloride, and also permits an effective return of the liquid 
material to the plant for a substantial part, as the recovery being 
contaminated to a very limited degree with the fume suppressive, due to 
the by far smaller density than that of the chloride.