DD263049A5 - Shaped morbid bodies - Google Patents

Abstract

The invention relates to shaped macroporous bodies suitable for removing carbonaceous and metallic contaminants, including nickel and vanadium, from hydrocarbon feedstocks by short term high temperature contact and consisting of mullite and crystalline silica. In the decarburization and demetallization process, the impurities are deposited on the solid particles and the bulk of the feedstock is evaporated. After burning off the carbonaceous deposits from the particles, the hot particles containing nickel and vanadium are returned and brought into contact with new charges of the contaminated feedstock. The metals are periodically removed from the coke-liberated particles by extraction with a mineral acid at elevated temperature, without any dissolution or other destruction of the alumina-silica particles. The particles are then returned to the system. The mullite-based and crystalline silica-based particles are obtained by calcining particles of highly pure kaolin or kyanite under controlled conditions to ensure substantial conversion of the silicate content of the clay or kyanite to a mixture of mullite and crystalline silica. Optionally, even small amounts of acid-unalloyable alumina may be present in the particles.

Description

reduce thermal cracking of the products. The particles of contact material, now containing the precipitates of the metals as well as sulfur, nitrogen and carbonaceous materials, are fed to the burner where the combustible impurities are oxidized and removed. The regenerated contact agent, which still contains the metals but less coke, leaves the burner and is fed to the contact zone for further removal of impurities in the feedstock. The selective evaporation can also be carried out in the manner known as the so-called. Moving bed using peletierter particles of the contact material, for. B. pellets having a diameter of 0.368 to 0.399 cm (0.145 to 0.157 inches) and a length of 0.254 to 0.762 cm (0.1 to 0.3 inches). Comp. See also U.S. Patent 4,435,272 to Bartholic et al. In practice, the metal content of the contact material in the system is controlled by the addition of fresh contact material and the removal of spent contact material. Thus, a high metal content can be maintained without adversely affecting performance.

Insofar as the contact material is substantially catalytically inert, only a slight conversion of the light gas oil fraction and even lighter fractions occurs.

As a result, the hydrogen content of these streams is maintained. In other words, the light components are selectively evaporated. The molecular transformation that occurs is due to the disproportionation of the heavy, thermally unstable compounds present in the residue feedstock.

The hydrogen content of the coke deposited on the contact material is generally lower than 4%. Coke formation is up to 80% of the Conradson carbon residue of the feedstock. The heat recovered from the combustion of the coke is used within the ART unit. Any excess heat can be used to generate steam or electricity.

A coke product is not formed. In contrast, lag and fluid cokes produce a coke product that is equivalent to 1.3 to 1.7 times that of Conradson coal.

In general, the metals accumulated on the contact material used in the ART process tend less to form coke than the metals deposited on the cracking catalyst. This has the consequence that the ART process still works effectively even with higher levels of metals on the contact material than can be tolerated in the operation of FCC plants in general. It was e.g. worked effectively when the total content of nickel and vanadium exceeded 2%, based on the weight of the contact material.

Criteria for suitable contact material have been developed in the development of the ART method (see US Patent 4,263,128). These concerned low catalytic cracking activity, less than 20% microactivity test (MAT test) conversion, and a surface area of generally less than 20 m ² / g (BET) and preferably in the range of 5 to 15m ² / g, and high resistance to abrasion. In this connection reference is made to the following US patents to David B. Bartholic as inventor: 4243514.4263128,43092274,4311 579,4311 580,4325809, 4374021 and 4427538. The abovementioned patents give preference to calcined kaolin-derived microspheres, in particular microspheres. as in the rise of naturally occurring hydrogenated kaolin in the water, spray drying to form microspheres, and calcination thereof at a temperature and for a time such that the clay exhibits the kaolin exothermic kaolin output.

The resulting microspheres are further characterized according to the aforementioned patents with base areas in the usual range, with the majority of the porosity being formed by pores having a diameter in the range of 15 to 60 nm (150 to 600 Å). An enumeration of other contact material can be found in the aforementioned US Pat. No. 4,243,514 in Sp. 5, lines 15 to 23. In accordance with the above preference of kaolin-based microspheres calcined to typical heat release, such microspheres are also used in the practical operation of ART systems. The ability of such microspheres to remove more than 90% of the metal impurities in heavy feeds and formation of synthetic crudes to reduce catalytic cracking has been confirmed. However, it has been reported that occasionally the microspheres tend to coalesce or agglomerate when the particles of contact material have been used for an extended period of time. Agglomeration or coalescence has been reported to occur in stanchions, cyclone diplegs, and regions of stagnant flow resulting in loss of fluidity and fluidity (see U.S. Patent 4,463,588 to Hettinger et al.). Two hypotheses, both relating to the influence of metals, have been put forward. The first was that microspheres of calcined clay were not sufficiently porous to absorb metals. The result of this consideration was that microspheres having a greater porosity were used, in particular those having a porosity of at least 0.4 cm ³ / g (see US Pat. No. 4,469,588). A similar concept can be found in US patent application SN 505650 to Speronello, according to which the transformation from clay to porous mullite is proposed by extending the clay beyond the "exotherm point" to form MuIMt and free silica, especially amorphous soluble silica, This leaching leads to the formation of pores, the other hypothesis being that vanadium forms compounds which have relatively low melting points and therefore are in a liquid state during regeneration For example, it was intended to provide means to react the vanadium compounds with inorganic compounds, such as those of titanium, calcium, magnesium or rare earth, to form vanadium compounds having higher melting points (see U.S. Patent 4,469,588 to Hettinger et al .).

A desirable embodiment of an improved selective evaporation process would be the removal of nickel and vanadium from the spent contact material. This would allow the reuse of such reactivated contact material in the selective evaporation process. This embodiment would lead to a more economical procedure. The overall economics of removing metals from spent contact material when reused in the process is dependent upon the type of metals removed and the complexity of the metal removal step. This would also allow the operation of a factory from which any non-sale product can be dumped in a land fill.

Kaolin clays are naturally occurring, hydrated aluminum silicates of the approximate formula Al ₂ O 3 .2SiO ₂ XH ₂ O, where X is usually 2. Kaolinite, Nacrit, Dickite and Halloysite are types of minerals from the kaolin clay group. It is well known that upon heating kaolin clay in air, a first change of state occurs at 550 ^° C. associated with an endothermic dehydroxylation reaction. The resulting material is generally referred to as metakaolin. The metakaolin is stable until heated to about 975 ° C and then begins to undergo exothermic conversion. This material is often described as kaolin subjected to the characteristic exothermic reaction. Some

Experts see this material as having an impurity aluminum silicate spinel or as a gamma alumina phase. Comp. Donald W. Breck, Zeolite Molecular Sieves, published by John Wiley & Sons, 1974, p.314-315). Upon further heating to about 1050 ⁰ C, the formation of mullite begins. The mullite formation reaction that takes place when kaolin clay is used as the sole source of silica and alumina can be represented by the following equation, provided that the approximate chemical formula for kaolin (without water of hydration as

Al ₂ O ₂ - 2SiO ₂ and the formula for mullite with 3Ai ₂ O ₃ .2SiO _{2 is} assumed: 3 (Al ₂ O ₃ .2SiO ₂ )>

3AI ₂ O ₃ · 2SiO ₂ + 4SiO ₂ .

The term "4SiO ₂ " represents the free silica formed as a result of the rearrangement in mullite. The extent of conversion to mullite is dependent upon the time and temperature as well as the presence of mineralizing agents known in the art A kaolin clay of high purity can theoretically be converted to 64% mullite by weight, the free silica formed in the thermal conversion of kaolin clay to mullite , is amorphous if calcined at about 1100 ° C. When heated to temperatures above about 1260 ° C., the silica crystallizes and the proportion of X-ray detectable silica increases with temperature and time The crystalline silica may be tridymite or cristobalite or as a mixture thereof Mullite is widely used for ceramic applications, such. B. in the production of refractory grains. For these purposes, dense, impermeable products are needed and porosity is undesirable (see, for example, U.S. Patent 3,462,505). It is also known that the reactivity of kaolin clays changes depending on these thermal transformations. on this the above-mentioned publication by Breck, p. 315.

The present invention is based z.T. attempts to provide a cost-effective technology for removing deposited metals, particularly nickel and vanadium, from spent contact material which is periodically withdrawn from ART units and replaced with fresh material. Previous attempts to remove larger amounts of both vanadium and nickel by acid extraction have had the disadvantage of the co-extraction of substantial proportions of alumina from the contact material formed when calcining kaolin clay microspheres during heat release. Removal of alumina to more than minimal proportions leads to an undesirable increase in footprint. These findings, known in the field of catalytic cracking, indicate that the increase in footprint is generally associated with increased cracking activity. Moreover, the removal of substantial alumina levels leads to a decrease in the abrasion resistance of the microspheres, or in some cases even to the destruction of the microsphere shape. In any case, the reuse of metal-depleted (extracted) microspheres as a total or partial replacement with a fresh feed of contact material is only possible to a limited extent. In addition to the aforementioned problems, the presence of alumina in the acid extract leads to difficulties in the subsequent separate recovery of nickel and vanadium from the extract. Simultaneously with the investigations directed to the formation of a contact material suitable for the simple acid extraction of metals, it has also been attempted to develop a contact material which is resistant to agglomeration. These efforts have been frustrated by the unexpected finding that the increase in porosity does not necessarily result in a decrease in the tendency to agglomerate. On the contrary, it has even been found that some materials which have the criterion of resistance to agglomeration are of very low overall porosity. Some materials had promising agglomeration resistance, even after one or two acid regenerations, but physically decayed when subjected to further cycles of metal loading and regeneration by acid extraction.

Object of the invention

The object of the invention is to provide an improved and economical process for producing high quality products from a batch of petroleum hydrocarbon feedstocks using molded macroporous bodies as contact material.

Explanation of the essence of the invention

The object of the invention is to provide an improved particulate contact material as well as an improved selective evaporation process for removing nickel and vanadium from the spent contact material.

According to the present invention, macroporous bodies formed as contact material are provided which combine mullite and crystalline silica and which are abrasion resistant and substantially insoluble in acids. Thus, according to the invention, these apparently unrelated problems are resolved with the unexpected discovery that, when using an alumina-silica contact material composed predominantly of mullite and crystalline silica, both problems are solved by chance. This was unexpected because the materials that formed the basis of this discovery, only had a low porosity, namely less than 0.1 cm ³ / g. Essentially, the total porosity was formed by macropores, ie pores with a diameter greater than 100nm (1000Å). In view of the many advantages that can be achieved with a contact material consisting primarily of crystalline mullite and crystalline silica, we do not want to be bound by any theory of hypothesis. We believe that such contact particles reduce agglomeration because they contain little, if any, silica which is not in crystalline form as mullite and crystalline silica. Consequently, less silica is present in chemically reactive form. Insofar as the major constituents of the binder of the agglomerates are mainly composed of silicon dioxide and sodium and vanadium rich crystalline phases, less binder is formed under the hydrothermal conditions present in an ART unit. We also believe that decreasing the level of reactive silica makes less vanadium and nickel appear as silicate compounds or complexes that are difficult to dissolve with strong mineral acids. Consequently, a greater proportion of both metals can be removed by the acid extraction.

Accordingly, the invention resides in the provision of improved particulate contact material characterized by the presence of both MuIHt and free silica (ie, silica in addition to the silica content of the mullite components), wherein a substantial portion of the free silica in crystalline form (tridymite, cristobalite or both). The majority of pores are in the macroporous region with minimal microporosity and mesoporosity. The contact particles may also contain small amounts of alumina which is not present in mullite, e.g. Aluminum oxide in crystalline form resistant to acids

 The present invention leads to the following improvements of the ART method:

1. Contact particles, which in fresh and regenerated (acid-extracted) state have acceptable resistance to abrasion and show low catalytic activity. '

2. Contact particles which, even in the metal loaded state during use in the ART units, may be subjected to repeated direct acid treatment for the effective removal of nickel and vanadium without the co-extraction of alumina.

3. Contact particles which have improved resistance to agglomeration in both the fresh and acid-extracted states. As a result, the microspheres can be repeatedly used, extracted and recycled to an ART unit without undesirable cracking activity or agglomeration tendency or reaching or decomposing during or after the acid treatment.

4. Contact particles which can be made from readily available mineral material.

In addition, according to the invention, a method for producing a new contact material is provided. For this purpose, a thermally mullite and free silica convertible clay or kyanite, which can also be converted into mullite and silica, are first mixed with a volatile binder, especially water, and the mixture is used to make particles of the desired strength and shape. Preferably, microspheres are formed by spray drying. The formed formed products are then heated (calcined) under conditions of temperature and time which result in substantial conversion to mullite and also sufficient to bring the silica resulting from the decomposition of the clay or kyanite into the crystalline state in sufficient quantity.

Furthermore, the invention comprises a process for the production of high quality products (premium products) from a. Petroleum hydrocarbon feedstock containing a significant proportion of Conradson carbon residues and metals, including vanadium and nickel. Here, the feed is contacted in a decarbonation and demetallization zone with a contact material consisting of mullite and crystalline silica. The contact material particles used have low microactivity for low stress kataytic cracking, including a temperature of at least 482 ° C for a time less than that for substantial cracking of the feedstock. At the end of the treatment time, the solid contact material is separated from the fraction of the feed which has been mainly vaporized to give a vaporized, decarboxylated and demetallised hydrocarbon fraction which has a lower content of Conradson coal and metals than the feedstock. The separated fraction is then cooled to a temperature at which no thermal cracking occurs.

The solid particles of the contact material now containing the metals and carbonaceous materials are then contacted with air at elevated temperature in a separate firing zone to heat the solid and remove the combustible deposits. At least a portion of the flowable solid particles are recycled from the firing zone to the decarbonation stage to further decarburize and demetallize the feedstock. Preferably, the metal-loaded particles periodically withdrawn from the firing zone are leached with a mineral acid to remove (extract) the majority, more preferably at least 80 wt%, and even more, preferably at least 90 wt%, of both nickel and vanadium; the metal-reduced particles are recovered and returned to the burner for reuse in the decarburization and demetallization. Preferred acids for removing nickel and vanadium are hydrochloric acid and sulfuric acid which are used at elevated temperature.

The invention will be explained in more detail with reference to the embodiments shown in the drawing. Show it:

Fig. 1 is a graph showing the extraction of metals (nickel and vanadium) from microspheres of kaolin clay which was in a muffle furnace at temperatures of 1149-1371 ° C calcined (2100-2500 ⁰ F); the graph includes the results obtained using two different clays;

Figure 2 is a flow chart of a preferred method of removing the metals from spent contact material by acid extraction followed by separate recoveries of nickel and vanadium from the extract.

The clay or kyanite to be converted into mullite / crystalline silica should be of high purity. In general, these minerals should have a low content of iron, titanium dioxide, alkalis and free alumina. Typical is a material containing at least 95% by weight (after removal of volatiles) of silica and alumina. At present, the high purity, water washed kaolinite clays are preferred from occurrences in the manner found in Georgia; such clays typically have a Si0 ₂ / Al ₂ O ₃ molar ratio of about 2: 1 and contain, on a volatility-free basis, less than 2% iron (determined as Fe ₂ O ₃ ) and less than 1% total alkali and alkaline earth oxides , Some fatone ^. Eg smectites, (ζ B. bentonites), attapulgites and lodge have a high content of alkalis and alkaline earths and some clays and kyanites are high in iron content, ie more than 3% calculated as Fe ₂ O ₃ on a weight basis (without volatile) shares). From the Georgia clays, both the hard and soft types can be successfully used.

The particle size distribution of the clay and the gradation of its degree of agglomeration in the green bodies, that is the bodies present after particle formation and before calcination, affects the hardness and the structure of the calcined particles. However, too much of the macroporosity can decrease the strength and abrasion resistance of the mullite crystalline silica body. Therefore, in terms of particle size and degree of agglomeration of the clay used to make the subject mullite / silica particles, there is a trade-off between maximum strength (i.e., minimum porosity) and some macroporosity. Clays with a broad particle size distribution generally result in minimal porosity. An example of such a clay is the hydrous ASP V2 900 kaolin,

Particle up to 20pm (microns) diameter contains at an average particle size (weight basis) of (microns) and about 25% by weight finer than 0.5μm (microns). Clays with a narrower particle size distribution do not compress as effectively as clays with a broader distribution, resulting in a greater proportion of macroporosity. An example of such a clay is the hydrous ASP '/ 2 400 kaolin which contains particles up to 20 microns in diameter with an average particle size of 5 microns but no 0.5 micron micron. A good compromise between these extremes, which results in a macroporosity of less than 0.1 cm ³ / g in the microspheres after calcination, the hydrous kaolin ASP 600 V2; this contains no coarser particles than 8pm (microns), has an average particle size of 0.9pm (microns) at a rate of 35% at 0.5pm. (In the present case, all particle sizes of the water-wet clays in the micron range are understood as those determined by sedimentation and therefore also referred to in the usual way as "equivalent spherical diameter" or "esd".)

A preferred source of hard clay is the coarse fraction of a crude kaolin obtained as a by-product stream in the commercial production of hard clay calcined clay pigments with low abrasion (see U.S. Patent No. 3,586,523 to Fanselow et al.). This by-product stream is formed when processed hard raw clay is processed in centrifuges to obtain a fine fraction fraction; this is typically 90% by weight finer than 1 micron and is then calcined. The result of using the by-product stream is that practically all of the raw clay emitted is supplied to consumption. The fine particle fraction is used to produce high quality, low abrasion clay pigments, which pigments are essentially mullite free. The remainder is used to prepare the mullite / crystalline silica contact material.

Moreover, the present invention provides new bodies consisting essentially of mullite and crystalline silica. Although it is also possible to produce bodies in which other, substantially acid-insoluble constituents are present. Examples of these acid-insoluble materials are certain crystalline forms of alumina, zirconia and silica. The source of these acid insoluble additive components may be a material that is normally soluble in acid but can be brought into the acid insoluble state by calcination. So z. For example, alumina may be added in the form of the aqueous (soluble) oxide, which is then converted to the acid-insoluble state during the calcination.

The acid solubility is determined by refluxing the solid bodies with a 35% sulfuric acid solution for one hour at a weight ratio of 3 parts of acid to a part of the solid particles. If alumina is used as an ingredient in the preparation of the contact materials, it should be used in a lesser proportion compared to the clay content. If the alumina were used in mixing with the kaolin clay in amounts greater than 15 parts by weight to 85 parts by weight of the clay in the formation of the microspheres calcined at 1115-1,370 ° C, excessive agglomeration of the contact material would result. Microspheres having an acceptable agglomeration performance after calcination at 1 26O ⁰ C can be obtained at a proportion of added alumina in the range of 45 to 75 parts by weight to 55 to 25 parts by weight of the clay, but the abrasion resistance is impaired. And this decreases progressively with increasing proportion of added alumina. Consequently, a contact material with too high levels of alumina additives may become too soft or degrade during the acid treatment. In any case, whether alumina or other acid-insoluble constituents are present or not, the bodies should contain no more than 3 to 5% by weight of total oxides of alkalis, alkaline earths and iron, since these affect the agglomeration resistance at too high a content.

The shaping can be carried out according to methods customary in practice. The microspheres can be recovered by spray-drying a slurry of the clay in water. It is also possible to add a volatile binder such as polyvinyl alcohol to the slurry prior to spray drying to provide additional strength of the green microspheres prior to calcination. A preferred method of forming the microspheres is to prepare a slurry of 65% by weight of the finely divided high purity wet clay (eg, ASP V2 600 clay) and 0.3% by weight tetrasodium pyrophosphate based on the clay in water and the slurry then to spray in a spray dryer, which is operated with a gas inlet temperature of 540 ° C and an outlet temperature of 120 ⁰ C. This results in microspheres having a macroporosity of 0.25 cm ³ / g prior to calcination, but no significant meso or microporosity. The particle size of the microspheres is in the range of 20 to 150 μm (microns); the average size is typically 60 to 90pm (microns).

Cylindrical shaped bodies (pellets) in the size range of 0.79 to 12.7 mm (1/32 "to 1/2") diameter can be made by extruding a mixture of three parts by weight of high purity Georgia kaolin clay and one part by weight of water using a strand extruder ( auger-type extruder) can be easily produced. , , Other Verformungsverfähren applied and other forms, such. B. with honeycomb structure, are provided. The control of the calcination conditions, such as time and temperature, affects various properties, e.g. B:

1. the extent of clay conversion to mullite and free silica;

2. the conversion of the free silica to the desired crystalline form;

3. The pore size, bulk density and footprint of the mullite / crystalline silica material.

Suitable calcination temperatures are those which result in conversion of the clay to mullite and crystalline silica in reasonably favorable times. The calcination temperature is dependent on the nature of the clay in the particles in a specific implementation of the calcination. This is evidenced by the data in the illustrative examples showing that hard clays can be worked at lower temperatures than soft clays. Impurities in hard clays that act as fluxes may be responsible. Suitable calcination temperatures and times in conventional muffle furnace with laboratory dimensions are given in the examples. The temperature-time relationships vary-as has been found-depending on the different muffle furnace. The results depend on the furnace used to calcine the particles. Rotating calcining ovens and multi-stage stove ovens are suitable. The most suitable conditions are easily determined for any given calciner. A suitable method for this is the following: The theoretically achievable mullite content is calculated from the chemical composition of the green, preformed particles. For example, the maximum mullite content is 64% using preformed microspheres of a high purity soft kaolin with a ratio of SiO ₂ / Al ₂ O ₃ of 2.0. When using a high-purity kyanite, the maximum mullite content is 88%. The rest is free in both cases

Silica. X-ray patterns were obtained from samples calcined at various temperatures and times to a detected mullite content very close to the theoretical maximum. In general, a mullite index above 50 should be obtained on calcining kaolin clay and an index above 45 on calcination of kyanite. The progress of the formation of crystalline silica can be monitored by determining the height of the peak at d = 0.411 nm (4.11 Å). As the mullite and crystalline silica phases form, the pore volume and footprint decreases and the bulk density increases.

Refreshing the substantially inert contact material in an ART unit depends on the amount of contaminating metals in the feed and the desired load of the feed. So zrB needs. a 350 tonne stock in an ART unit processing 50,000 barrels of feedstock per day with 150 ppm nickel and vanadium, a withdrawal and loss rate of 42 tons per day to maintain a 3 wt% loading of nickel and vanadium the circulating contact material. The daily deduction and loss of contact material is replaced by the addition of fresh contact material. The metal-loaded microspheres withdrawn from the ART unit burner typically contain from about 0.5 to about 0.01 weight percent coal. The vanadium may be in the five- or four-valent oxidation state or both. The oxidation state of the vanadium varies depending on the proportion of excess oxygen in the burner.

The acid leaching reactivation process, as illustrated in FIG. 2, is employed to recover the metals (nickel and vanadium) from the spent contact material after being withdrawn from the burner of an ART unit and to form a reactivated contact material is useful for reuse in the same or another ART unit. The current preferred method uses a high temperature mineral acid to remove the metals from the substrate material followed by filtration to separate the metal-containing solutions from the contact material. The metals are purified in separate process steps and can be sold as by-products. Hydrochloric acid and sulfuric acid extraction at temperatures above about 88 ° C have been used successfully. A flow chart for the currently preferred process is shown in Fig. 2 and described below.

The first process stage 1 removes foreign matter and oversized material using a screening stage. This stream should be suitable for deposit in a standard landfill. However, care may also be taken to treat this material prior to deposition, if desired.

The second stage 2 is a high temperature (649-871 ⁰ C) -Fließbett contacting step in the presence of oxygen to remove carbon from adhering to the contact material and to oxidize the Vanadiumsauf the substrate to the +5 oxidation state. This oxidation is necessary if vanadium is to be recovered as vanadium pentoxide of high purity. In the event that the vanadium is to be recovered as vanadyl sulfate or in the form of other vanadyl salt, the stage 2 can be omitted.

The stream of contact material is then fed to the acid pretreatment stage 3, where it is contacted with hot sulfuric / coarse acid (monoperoxide sulfuric acid), preferably above about 88 ° C. The leaching is carried out for about 30 minutes at a weight ratio of the liquid to solids of 1.5: 1 to 3: 1. The strength of the acid is about 20 to 35% by weight. The concentration of Caro's acid is set at about 1 to 1-fold of the stoichiometrically required amount to react with the vanadium portion present. This acid can be prepared in a separate, cooled tank 4 prior to acid leaching. Other methods of oxidizing tetravalent into pentavalent vanadium may be used, e.g. As electrolytic processes, ozone treatments, treatments with inorganic salts, such as chlorates, persulfates or other known in practice oxidants. When the vanadium is recovered by liquid ion exchange (LIX treatment), it is preferred to use a filtrate having a pH of 0.3 to, preferably about 0.8. The pH of the filtrate is affected by the concentration and amount of acid.

The resulting slurry from the acid treatment stage is fed to a filter 5 to separate the contact particles from the metals in solution in a countercurrent washing system. The washed filter cake from the filter 5 is fed to a flash dryer 6 and dried there to a moisture content below 1%. This dried material is the reactivated mullite / crystalline silica product suitable for reuse in the ART process. The filtrate from this stage is fed to the metal recovery part of the process. In this section on recovering the metals, the vanadium is first removed from the solution by liquid-ion exchange (LIX) and then the nickel is recovered by selective precipitation. During the vanadium recovery by LIX, the stream from the acid treatment containing the filtrate and the washing is brought to a pH of 0.8 to 2.5 in the LlX stage 8 in the stage 7. In the LlX stage, this stream is contacted with such a stream containing "Alamin E 1/2 336" in an organic diluent The vanadium ions in the aqueous solution are exchanged with the sulfate ions by the organic Alamine 336 stream. The vanadium-poor aqueous stream is fed to a further treatment described below: The vanadium-containing organic stream is stripped to recover the vanadium as the ammonium metavanadate and return the organic phase to the LIX unit The ammonium metavanadate is converted to a 98% vanadium pentoxide black flake form in a two-stage furnace system 9.

The low-vanadium aqueous stream from the LIX unit is passed to a pH adjustment tank where the pH is raised to 4.5 to 5, followed by the precipitation of aluminum, iron and minor amounts of vanadium ions. The slurry is sent through the filter 11 to recover the precipitate.

The filter cake from the filter 11 is transferred and treated in a subsequent process section of the system (16-20). The pH of the filtrate in the tank 12 is increased to 8.0 for the purpose of precipitating hydrated nickel oxide. The nickel precipitate is recovered in the filter 13 and dried in a dryer 14. The filtrate from this stage is evaporated in a crystallizer 15 to obtain sodium sulfate as a by-sale by-product. The mother liquor from the crystallizer 15 is combined in the tank 16 for disposal along with the alumina / iron precipitation. The resulting liquid filtrate, which contains only sodium and calcium ions, is passed through a replenishment stage 17, a filling stage 18 and a filter 19 into a designed basin 20 for storage and reuse. Representative spherical contact materials according to the invention can only be prepared from high purity kaolin clays having a particle size distribution suitable for turbulence. Typically, the average particle size is 60-90 μηη (microns). The particles should be essentially catalytically inert, that is, the activity

(Conversion) is less than 20 and preferably less than 10 when measured by the Mat method. This process is described in European Patent Application 8410946.6. The bulk density is in the range of 1.1 to 1.5 cm ³ / g. The EAI value is less than 2% / sec. preferably below 1% / sec. and most preferably below 0.5% / sec. The pore volume is less than 0.1 cm ³ / g, z. B. 0.01 to 0.09cm ³ / g. The pore volume typically moves at pores with diameters greater than 100 nm (1000 Å).

The agglomeration of the metal-loaded microspheres should be less than 45, preferably less than 25, according to the method of determination as described below and expressed as the mean particle size. In the case of refluxing with 35% sulfuric acid for 1 hour at a liquid / solid ratio of 3: 1, the alumina content should be reduced by not more than 5% by weight, preferably less than 3% by weight; the EAI value of the microspheres should remain substantially unchanged and the base should not exceed 20m ² / g. The footprint of fresh microspheres is at most 20m ² / g, preferably less and significantly less than 5m ² / g, e.g. B. 1-3m ² / g. Preferably, more than 80% of the deposited vanadium and nickel should be accessible for removal by extraction. In particular, the removal of nickel and vanadium should be greater than 90%. Also in the case of previously used microspheres, the deposits of nickel and vanadium should be removed by more than 80%, preferably more than 90%, by the acid treatment, while reactivated microspheres having physical and functional properties will result in the same as fresh microspheres. One possible departure is that the resulting reactivated microspheres can increase in surface area, but preferably not to levels in excess of 20 m ² / g According to a particular preferred embodiment, the microspheres are intended for a plurality of cycles, e.g. more cycles of metal loading and reactivation by acid extraction may be appropriate to ensure microcuge which has physical and efficacious properties similar to those of fresh microspheres Definition and details of the methods of investigation used herein:

Mullite Crystal Phase Identification Using X-Ray Pulse Counting: As a reference pattern for the mullite X-ray powder refractive image, the X-ray powder refractive index chart of Leonard G.Berry, Joint Committee on Powder Diffraction Standards, 1601 Park Lane, Swarthmore, Pa. 19081, from 1972, card no. 15-776 used.

The mullite index is measured by a standard quantitative X-ray diffraction technique based on the 100% mullite reference and using copper K alpha radiation. A mullite index of 100 indicates that the MuIMt X-ray peak intensity at the peaks of 16,33,40 and 60 ° has 20 intensities corresponding to the 100% MuIMt reference.

Identification of tridymite and cristobalite crystal phases using X-ray diffraction: It is known that quantitative analyzes of cristobalite or tridymite phases by X-ray diffraction are very difficult because of the effects of crystal distortion and the lack of a suitable standard. Qualitative phase determination can be achieved for cristobalite according to map no. 11-695 and for tridymite according to maps no. 18-1169 and 18-1170.

Base Area and Volume of Pores in the range of 2 to 10nm (20-100Å): The footprint and volume of pores having diameters in the range of 2 to 10nm are determined by conventional nitrogen adsorption and desorption techniques, e.g. Using a device named "Micromeritics V2 Digisorb 2500 Automatic Multi-Gas Surface Area and Pore Volume Analyzer." Prior to examining the footprint and volume of pores having a diameter in the range of 2 to 10nm, the material will first pre-treated by heating in vacuo at about 250 ° C for 16h. volume of pores in the range of 10 to 200nm (100-20000A): the volume of pores of this diameter is determined by a standard mercury-intrusion pore measurement technique using a scanning mercury porosimeter, such as that manufactured by Quantachrome Corp.. the interrelationship between pore diameter and intrusion pressure is calculated using the Washburn equation and assuming a contact angle of 140 ⁰ C and a surface tension of 484.10 ^"7 3 / cm ^2.

Before this determination is made, the particles to be examined are pretreated by heating in air to about 350 ⁰ C for hrs., And cooling in a Dessiccator. The term "total pore volume" as used herein in the specification and claims refers to the pore volume present in pores with diameters in the range of 10 to 2000 nm.

Micropores: Pores with a diameter below 10 nm (100 Å) are determined by nitrogen porosity measurements. Mesopores: Pores with diameters in the range of 10 to 60nm (100-600Å) are determined according to the mercury porosimetry.

Macropores: Pores with a diameter in the range of 60 to 2000nm (600 to 20,000 Å) are determined by means of mercury porosimetry.

Engelhard Downforce (EAI) Test: Preferably, the microspheres used in the ART process should be hard enough not to exhibit excessive abrasion in the selective evaporation unit. For example, the Engelhard attrition index (= "ΕΑΓ 'value) of the microspheres used should preferably be less than 2% / sec. more preferably less than 1% / sec. and in particular less than 0.5% / sec. The EAI value is determined according to a method as described in the publication entitled "Engelhard Attrition Index." A copy of this publication is in the library of the Engelhard Corporation Technical Information Center, Edison, New Jersey 08818 (Dewey Decimal No. 665.533EC / EAI) Access to this library may be obtained by writing to or telephoning the Manager from the Technical Information Center or by sending a copy to: Director of Patents, Engelhard Corporation, Edison, New Jersey 08818.

Bulk Density Determination: The apparent packing density or apparent bulk density of the shaped particles is determined according to a procedure substantially as described in ASTM Specification D-4164-82, provided that a 100 ml sample is used and 5000 strokes (taps ) be applied.

Stress Agglomeration Test: To this end, a method was developed that determines the tendency of the materials to agglomerate under conditions determined by the selective evaporation process described herein. In general, the change in the particle size distribution of a sample is tested after being subjected to high-temperature steaming. In particular, this method provides for the following treatment steps: (a) a sample is sieved under vibration in a rotary (Rotap) apparatus by means of a 70 mesh sieve for 20 minutes;

(b) weighing 25g of the -70 mesh fraction;

(c) the particle size distribution of the 25 g sample is determined under vibration in the Rotapapa for one minute by sieving using a collection of sieves having mesh sizes of 70, 100, 140, 200 and 270;

(d) The 25 g sample is then placed in a porous basket of "Inconel" alloy (or other porous basket such as alumina) and the basket is then placed in an oven exposed to 100% steam during Flows through 48 hours at a temperature of 871 ⁰ C;

(e) the 25 g sample is taken and the particle size determination as given in (c) is repeated;

(f) the mean and median particle size distributions of the 25 G sample before and after steam treatment are calculated taking into account the following equations:

(wd)

dmean =

dmedian =

antilogue (w · logd)

where dmean mean particle size, median mean particle size (both in pm (microns), w the weight of a particle size fraction, and d the particle size, which are as follows

described is described:

Particle size of fraction particle size in

from the sieve with mesh width pm (microns)

+70 250

-70 / + 100 177

-100 / + 140 125

-140 / + 200 88

-200 / + 270 63

-270 44

(g) the differences between the mean and median particle size and after the steam treatment described in (d)

are calculated according to the following equations:

ömean = dmean after the steaming -dmeanbefore steam treatment

Smean = dmediah after steaming -dmedian before steaming.

The ömean and ömedian contained in this material for a material are evidently a suitable measure of the agglomeration fraction which occurs when this material is used in the course of the selective evaporation of the type described here. In particular, materials with high ömean and JJmedian values appear to have a greater tendency to agglomerate in the evaporation process than those having lower ömean- and 5median values to determine the effect of the presence of vanadium on the agglomeration tendency of the When various amounts of vanadium were applied to individual samples, these samples were then tested for determination of ömean and ömedian values Because, in a selective evaporation process of the type described herein, nickel is also typically deposited on the particulate contact material, nickel also has grown deposited on the particles.

Typically, the samples were loaded with 8 wt% of the metals at a weight ratio for V / Ni of 4: 1. Metal Application:

The method of applying (impregnating) the metals used in the illustrative examples is to contact pure microspheres with dilute aqueous solutions containing nickel nitrate (Ni (NO ₃ J ₂ .6H ₂ O) and ammonium metavanadate.) The metals are applied to the microspheres in a V / Ni weight ratio of 4: 1, an application of 9.16 g of nickel nitrate in 35 ml of water and ten applications of 1.7 g of ammonium metavanadate in 35 ml of hot water are performed to obtain 100 g of pure microspheres at 6.4% vol and 1.6% Ni. A batch of the pure microspheres is placed in a shallow dish, whereupon small amounts of the aqueous solutions are added and mixed with the microspheres to form a paste The paste is heated in a convection oven at a temperature of 110 ⁰ C dried. the resulting cake is broken up in small lumps, and a further part of the aqueous solution may be applied. Due to the h Without solubility of nickel nitrate, the required amount of nickel can be applied to the microspheres in a single application of the solution; however, in the case of the ammonium metavenadate, because of the very low solubility, many applications of the aqueous solution are required to obtain a vanadium loading of more than 0.76%.

The metals are dispersed in the microspheres in a series of conditioning steps. Thus, the metal-loaded samples are first calcined at 593 ⁰ C in a muffle furnace for one hour and then at 760 "C in a fluidized-bed tube reactor for 4 hours steaming. This steam treatment of the impregnated particles with 100% steam at 760 ⁰ C for 4 hours is described in "Appendix A" of the publication entitled "Engelhard Procedures for Hydrothermal Deactivation of Fluid Catalytic Cracking Catalysts." This publication is in the library of the Technical Information Center, Engelhard Corporation, Edison, NJ 08818 (Dewey Decimal Number 665,533 Ec Access to this library, including this publication, may be obtained by writing or telephoning the Manager from the Technical Information Center or by sending a copy to: Director of Patents, Engelhard Corporation, Edison, New Jersey 08818.

The sample is then passed through a 70 mesh screen for 20 minutes via a Rotap sifter apparatus. This screen not only breaks up the soft agglomerates, but also removes foreign material, such as any "chunks" of metal salts, and the sample is ready for the test.

Ausführungsbeispiei

The following examples are intended to further illustrate the invention, but not to limit it.

example 1

This example illustrates the preparation of mullite / crystalline silica macroporous low pore volume flowable microspheres from both hard and soft kaolin clays; it shows that both types of clay result in contact material particles that can be reactivated with hot sulfuric acid to remove over 80% without substantial aliquot extraction of alumina. The example further illustrates how the calcination conditions alter the physical properties and affect the extraction of nickel and vanadium. ASP 1/2 600 kaolin clay (soft kaolin clay) is pasted into water at a solids content of 60%, which contains 0.3%, based on the dry weight of the clay, of tetra-sodium pyrophosphate as a dispersant. The slurry is in a nozzle spray dryer (Bowen system) dried under the following conditions: inlet temperature 300 to 350 ⁰ C, outlet temperature of 120 to 15O ⁰ C, backside pressure -5,6-10 ⁵ N / m ² (80 psig), front pressure ~ 1.7 · 10 ⁵ N / m ² (25 psig) and relative feed setting 0.2.

The average particle size of the microspheres is 75-85pm (microns) in diameter.

Parts of the microspheres are calcined at temperatures of 1149 to 1371 ⁰ C for 2h. in a muffle furnace (Harrop system). During the calcination, the microspheres were kept on cordierite trays which were left uncovered. The procedure was repeated with a mixture of the coarser "waste" fractions of hard Georgia clay known as "Dixie" clay, these coarser fractions being obtained from a plant by the following procedure: raw Dixie clay in water stirred, freed of particles larger than a 325 mesh sieve and then fractionated in a standard "Bird" centrifuge to obtain a finely divided fraction of approximately 90% finer than 1 micron as a centrifuge overflow product. The underflow products containing the so-called coarse rejects are collected and screened to remove the 325 mesh particles, and portions of the sieved suspensions are centrifuged in a Pilot Bird centrifuge to obtain a finely divided fraction with an average particle size of 0.4 μm (micron) at a level of about 78% by weight finer than 2 μm (microns) The suspensions are flocculated with sulfuric acid, filtered and redispersed at a solids content of 60% with the use of tetrasodium pyrophosphate before Spray drying as described above Parts of the spray dried microspheres are calcined as described below The properties of the calcined microspheres of ASP 600 clay and Dixie clay are shown in Table I. The resulting calcined microspheres were then added as 3 wt% Metals (2.4% V and 0.6% Ni) impregnated and later reactivated.

The typical laboratory reactivation procedure consists of weighing 50g of the metal loaded microspheres into a 100ml column flask containing 85g of a 35wt% sulfuric acid (liquid / solid ratio 1.7) and equipped with a magnetic stir bar 2.5cm in length , The flask is connected to a reflux condenser and heated to boiling over a heating mantle. The time of leaching is measured from the onset of reflux and typically lasts one hour. The slurry is stirred at a minimum rate which prevents settling of the microspheres. After one hour, the slurry is filtered through a medium-pored sintered glass filter; the solids are washed twice with about 20 ml of deionized water. Thereafter, the reactivated microspheres are oven dried at 110 ⁰ C and then examined for various physical or physical properties to and determines the residual content of nickel and vanadium. For comparison purposes, commercially available contact material is reactivated and evaluated. This material was prepared by calcining soft Georgia kaolin clay microspheres to the exothermic transformation point and had a mullite index of 5 (Sample A). For further comparison, a contact material also made of soft clay was used which had been calcined to a mullite index of 39 (sample B) and was also examined after reactivation. The physical properties of the microspheres before and after the sulfuric acid reactivation are shown in Table II (Dixie clay) and Table III (ASP 600 clay). The metal analyzes and physical properties of reactivated microspheres are measured after acid extraction to determine both the effectiveness of removal of nickel and vanadium, as well as to detect possible changes in the properties of the resulting reactivated microspheres, rendering them unsuitable for reuse in an ART unit would. The results for nickel and vanadium extraction of Dixie clay microspheres from ASP 600 clay are set forth in Figure 1 and Tables IV and V.

It was found that nickel could be extracted only slightly (20%) from conventional contact material (Control A) by the reflux treatment with 35% sulfuric acid, whereas the vanadium extraction was only good (63%). The extraction of vanadium and nickel from the other common material (Control B) was better (75% Ni and 80% V). The results for the inventive samples obtained by calcining microspheres of ASP 600 clay and hard clay show that nickel extraction increases rapidly with calcination temperature over the range 1093 to 1260 ⁰ C and then more slowly 1260-1371 ⁰ C. Vanadium extraction from soft-clay microspheres shows a linear increase with increase in the calcination temperature, whereas hard-clay microspheres have a larger extraction increase between 1204 and 1260 ^° C. than the calcination temperature.

The microspheres with the mullite index of 39 (Control Sample B) show a metal extraction performance corresponding to the at Caclinierungstemperaturen 1204-1260 ⁰ C. In addition, the physical properties of this contact material are comparable to Donen from ASP 600 clay microspheres obtained by a laboratory calcination at 1 204 ° C.

Blank IV and V recognize the results in Fig. 1 and the tables that calcination temperatures are required in excess of 126o ⁰ C and 1316 ° C for microspheres of hard clay and soft clay in order to achieve a greater than 80% metal extraction.

The results in Tables II and III show that the sulfuric acid activation has little influence on the physical properties except for a slight increase in the area. As stated above, a calcination temperature of 1316 ° C is necessary when using microspheres from the soft clay. Such conditions for calcination result in reactivated products with footprints in the range of 10 to 12m ² / g. These values correspond to those of commercial used contact materials; In that regard, it can be assumed that they bring only minor problems in repatriation. Meanwhile, ^0, a reduction of the base surface on a portion von4bis5m ² / g are obtained with a C Calcinierung.von 788-982.

Example 2

Samples of ASP 600 kaolin that had been spray dried and calcined in a muffle furnace at temperatures of 1149 to 1371 ^° C were tested to determine their behavior when used in an ART unit and showed the following characteristics: EAI less than 0.5 % / s Leachability of nickel and vanadium plots greater than 80% (Ni and V) with 35% sulfuric acid under reflux conditions and resistance to agglomeration according to the static agglomeration test below 25. The results are summarized in Table VI recorded with other properties. In the agglomeration test, the metals were deposited to a total of 8% to show a distinction between the samples. During leaching, the metals were applied at a total of 3%. Calcined microspheres with excellent agglomeration performance, ie less than 25, also show excellent metal extraction results, ie more than 85% are removed from both nickel and vanadium.

Example 3

The catalytic properties of the ASP 600 microspheres, calcined at 1149 to 1371 ^° C., are determined according to the MAT test; the results are summarized below: Catalytic properties of the ASP 600 microspheres:

rehearse calcination water Around Kok! No. approximately tem- material wall % ator ° C % % 238 1149 0.02 5.92 0.71 239 1204 0.02 4.66 0.60 240 1260 0.01 3.26 0.37 241 1316 0 5.37 0.3 242 1371 0 2.17 0.16

Example 4

Production of Raw Kyanite Microspheres:

The crude material was an uncalcined, high purity kyanite having the following composition:

Al ₂ O ₃ : 57.93% TiO ₂ : 0.93%

SiO ₂ : 40.69% CaO: 0.02%

Fe ₂ O ₃ : 1.0% MgO: 0.04%

K ₂ O: 0.02% Na ₂ O: 0.09% LOI: 0.34%

The material had a particle size of about 90% corresponding to a 325 mesh screen.

The material was ground liquid and then treated in a ball mill for 20 hours at a solids content of 60% with the addition of 0.3% Calgon T as a dispersant; Agates were used as a grinding medium in the 5.6 times the weight of the

Kyanits. The average particle size after treatment in the ball mill was 1.5μηη (microns).

The ball milled product was treated with sodium silicate (type "N" brand) in an amount of 3%,

based on kyanite weight, and then spray dried.

The spray dried product was calcined in a Harrop oven to obtain the following properties:

Calcination temperature 126O ⁰ C

Treatment time 1 hour

Hg pore volume cm ³ / g 0.27

BET surface area ² / g 1.5

EAI% / s 1.4

Larger amounts of calcined kyanite were prepared to determine agglomeration. These samples were prepared from microspheres recovered using a 3% sodium silicate binder.

The only differences between these samples and the earlier ones were the longer residence time in the furnace and the

Sodium silicate content as a binder.

Parts of these calcined microspheres were examined for their physical properties. Others were loaded according to the impregnation technique described above to a total metal content and their agglomeration behavior

examined. The results are summarized below:

Kyanite microspheres

° C / 2

Calc.-Bding. (° C / h) 1148 ° C / 2 1260 ° C / 2 13 " Agglomeration, 5% metals δ mean μιη (micron) 69.3 4.9 5.7 ömedian um (micron) 54.7 4.9 5.5

74 -13- 263 049 47 .2834 .2713 5300 4400 530 440 1.3 1.7

Physics. Properties of Pure Microspheres Mullite Index 0 *

Hg pore volume cm ³ / g 0.2667

average pore radius Ä 3500

nm 350

Base area m ² / g 2.0

* Noise peaks - value may not make sense

Example 5

This example illustrates the preparation of a flowable, spherical contact material from mixtures of high purity kaolin clays with various calcined and hydrous aluminas. The clay materials used were the above-mentioned ASP 600 kaolin clay and a hard kaolin clay having a nominal particle size of about 80% to 2μηη (microns) and, as described above, from a discharged sidestream coarse-grained hard clay fraction to obtain the fine-particle fraction was made. The aluminas were: Alcoa A-3 type calcined alumina, FGA type calcined alumina, and TGA transition alumina, all obtained from Reynolds Metals Company. The proportions of alumina mixed with the clay were varied, ranging from 15 to 75 parts by weight of alumina (anhydrous basis) to 100 parts by weight of the total mixture (dry weight basis).

The preparation of the contact material based on the clay-aluminum oxide mixtures was carried out as follows. Tetrasodium pyrophosphate was added to the water in an amount of 0.5% by weight, based on the clay content of the mixtures. The pH of the pyrophosphate solution, initially 9.8, was adjusted to 7.0 by the addition of concentrated phosphoric acid. Mixtures of clay and alumina are added to the resulting solutions, setting a solids content of 60%. The slurries obtained wur'den in a "Cowles" mixer worked and then in a spray dryer (System Stork-Bowen) dried The operating conditions of the spray dryer were:. Inlet temperature 250 to 260 ⁰ C, outlet temperature 110 to 120 ° C, nozzle pressure ~ 2 5 × 10 ⁵ N / m ² (35 psig) and pressure drop 6 to 7 in water column 500 g of each sample were calcined in a Harrop oven at two different temperatures (1260 and 1371 ^° C.) for two hours.

Examples

The pore size distributions (mercury of the calcined clay spheres of Example 1 and Control Samples A and B are summarized in Table VII.) The preferred microspheres with excellent metal extraction performance and low agglomeration tendency exhibit a low total pore volume and contain predominantly samples with diameters greater than 100 nm (FIG The measurements of the nitrogen pore size distribution also show that the preferred microspheres have little or no micropore volume.

ω ο

bo CJl

to O

TABLE I Physical properties of the microspheres

sample used calcination Bulk density. "^ 1.17 total Basic fact EAI% / sec. Mil lit Index Cristobal it A teak No. Tone terop. ⁰ C % / Ατι area m / g m ² / g d = 4.11 't-shirt ·' 23 " ASP 600 11 * 9 0239 7.5 0.62 16 2 39 1204 0188 5.5 12:42 37 7 * 0 12f> 0 0134 2.9 12:22 52 241 1316 0081 1.6 12:25 53 2 * 2 1371 0037 1.0 12:20 58 "- 25 * ASF 600 114 9 ' 0248 β. β 1:00 7 Nothing \ 30. 755 (Repeats) 1204 0210 6.9 0.67 26 37 .34 256 l2ftO 0150 3.9 / 12:37 49 303 .34 257 1316 0094 1.8 12:29 52 102 * .30 25 " 1371 0046 1.2 12:19 59 1 * 14 - - 2 * 5 Coara "DlMl" 1149 0204 7.4 0.74 I * I * - 246 7 * 7 (-325 mesh) 1760 1371 0.082 0.017 0.5 0.7 I.O. 0.59 50 54 73 * 894 7 * 8 Coara · Dtil « 1093 0.2) 9 17.) 1.20 " H it Ί / C .62 249 [Cut 78% too 1149 0212 8.8 1:00 13 25 .46 250 2 μη) 120 * 1.26 0151 5.7 12:47 29 59 .28 251 1260 1:38 0057 0.7 0.60 53 751 • 28 257 1316 .43 0024 0.5 0.93 5 * 1129 .76 253 1371 1:45 0022 i.j 12:41 5 * 11 * 2 .14 .21 .32 .42 .49 .21 .40 .45 .10 .18 .29 .45 .46 1:49

* Peak height is a very good measure of the constituent 1 concentrate! ons .;

Peak width is a qualitative measure of the degree of crystallinity ** determined by Hg porosimetry (volume of pores with diameters

between 10 and 2000 nm (100 to 20000 Å).

ω ο

to O

cn

cn

TABLE II

Properties of Caicin Dixie-Toη hard and dry microspheres before and after reactivation with sulfuric acid

Sample. No. Calcination temperature ( ⁰ C) ·. after calcination Hg PV * 3 cm / g EAI · W see.) Mullite index after impregnation and Hg ₃ PV * cm / g Reaktivierunc ) Hillite Index IU * j Basis (m / g). ,, 1 12:21 1.0 13 Reason! Times (πΓ / g) 0.2) EAI (% / sec.) 39 120 * i B.β, 0.1) 12:47 29 17.3 12:20 0.64 42 1260 ii ; 12:06 .0.60 > J J 3.J 12:06 Oil ) 3 1116 O.; 12:02 0.9) 54 12.7 12:06 12:29 56 1) 71 o.j; 12:02 12:41 54 11.0 0.0) 12:36 ) 7 1.) 9.2 1.28

* PV = pore volume

cn

cn

TABLE III

Properties of ASP 600 calcined microspheres before and after reactivation with sulfuric acid

calcination after calcination Hg PV * 3, cm / g EAI (% / sec.) Mullite Index · after impregnation and reactivation Hg PV * cm / g EAI (% / sec.) Millit index sample Tenperature ( ⁰ C) Grundf1äche 12:24 0.62 16 Basic area (m ² / g) 0.23;   12:57 34 No. 1149 7.5 12:19 12:42 37 19.6 0.18; 12:51 46 1204 5.5 12:13 12:22 52 17.1 0.11> 12:24 42 1260 2.9 12:08 12:25 53 12.3 12:07 12:20 57 1316 1.6 12:04 12:20 58 10.3 • 0.03 12:18 58 1371 1.0 7.8

* PV = pore volume

ω ο

cn

TABLE IV

Extraction of V, Ni and Al O ₃ from microspheres made of Dixie clay with 35% sulfuric acid

Sample No. Calcination Tenperature ( ⁰ C) Initial content of metals (%) the Metal final content (*) ^ extraction nl Al ₇ O ₁ * V nl V hl V 41.7 6.1 249 1149 2.25 12:37 1.17 12:35 6.30 " 50.9 4.6 250 1204 30.2 0.60 1:03 12:26 57.6 79.2 3.0 ; 251 1260 2.25 ' 0.61 12:50 ò.ó; 79.0 92.6 2.3 252 1316 ' 2.29 I 0.63 12:46 12:03 SI.2 90.9 1.9 233 1371 2:45 0.62 12:44 12:06 83.2

b) Based on the Al "0., - Gehal t in the metal-free microspheres

ω ο

to O

TABLE V

Extraction of V, Ni and Al ₂ O ₃ from calcined microspheres, prepared from ASP 600 clays, by 35% sulfuric acid

Sample No. Calcination Tenperature ( ⁰ C) Initial Metal1gehalt Ni final metal NI ^ extraction nl Al ₁ O ₁ * V 12:57 V 12:27 ν 53 8.2 238 1149 2:34 0.60 1:07 12:16 56 · 71 6.5 239 1204 2.22 0.66 0.81 12:07 64 82 1.9 240 1260 2.23 0.64 12:55 12:05 71 85 1.3 241 1316 2.13 12:58 12:40 12:05 81 95 1.0 242 1371 1.93 12:42 12:31 12:35 85 21 5.5 Comparison A - 5% mil lit 1:59 0.61 0.61 12:17 63 75 4.9 Comparison B - 39% Mill it 2:32 12:50 80

b) based on the Al η content in the metal 1 frei en microspheres

2 3

ω ο

to cn

to O

TABLE VI

Physical and behavioral properties of microspheres from calcine ASP 600 clays as a function of the calcination temperature

Sample No. Curing temperature ⁰ C Bulk density g / cm Multi-index Pore volume cm / g ι EAI% / sec. Behavior in agglomeration test (Mean, un (micron) Leaching of Ni and V% * K.O. 2) 8 1149 1.17 16 0239 0.62 109 7OX or below 239 1204 1.26 37 0188 12:42 99 I 240 1260 1.3 ' 52 0134 12:22 43 241 1316 1:43 53 O.OSI 12:25 1.2 85Z + t 242; 1371 1:45 58 0037 12:20 O ' I i Comparison A Comparison B 1.07 1.16 5 39 0.26 0.16 1.0 0.21 : 55 80

not determined at 8% metal content

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Claims (33)

1. Shaped macroporous bodies such as vortex-capable microspheres and in the form of pellets, honeycombs and the like extrudable forms, characterized in that they combine into mullite and crystalline silica and are abrasion-resistant and substantially insoluble in acids. 2. Body according to item 1, characterized in that in addition to the alumina contained in the mullite still contain a small amount of acid-insoluble alumina. A body according to item 1 or 2, characterized in that it contains substantially all of the silica in the mullite and crystalline silica, and substantially all of the alumina in the mullite or a combination of mullite and acid-insoluble alumina is present and is present at least 95% by weight of SiO ₂ and Al ₂ O ₃ . 4. Mikrokugein according to item 4, characterized in that the pores are predominantly greater than 10O nm (1000Ä) in diameter and pores smaller than 10nm (100Ä) in substantial quantities. 5. microspheres according to item 5, characterized in that a total pore volume below 0.1 cm ³ / g. 6. microspheres according to one of the items 4 to 6, characterized in that they have an EAI value below 2% see. to have. 7. microspheres according to one of the items 4 to 6, characterized in that they see an EAI value below 1%. to have. 8. microspheres according to one of the items 4 to 8, characterized in that they have a BET surface area below 20m ² / g 9. Microspheres according to any one of items 4 to 9, characterized in that they have a mullite index of at least 45. 10. Microspheres according to any one of items 4 to 10, characterized in that they have an agglomeration resistance below 25 in the case of the measurement according to the static agglomeration method described above at a metal loading of 8Gew .-% nickel and vanadium and a vanadium / nickel weight ratio from 4/1. A body according to any one of items 1 to 11, characterized by being swirlable microspheres composed of at least 95% by weight of combined silica / alumina, consisting essentially of mullite crystals and crystalline silica, substantially all of them Silica is present in the microspheres in the mullite and as crystalline silica and substantially all of the alumina is present in the mullite or in the mullite and as acid-insoluble alumina, an EAI below 1% / sec, a footprint less than 5m ² / g Total pore volume below 0.1 cm ³ / g and such a pore structure have that the majority of the pores have a diameter of more than 100 nm (1000 Å). 12. Microspheres according to item 12, characterized in that they have a bulk density in the range of 1.1 to 1.5 g / cm ³ . 13. Microspheres according to item 13, characterized in that they have a SiO ₂ / Al ₂ O ₃ molar ratio of about 2 and obtained by calcining microspheres of high purity kaolin at a temperature and for a time sufficient to form a mullite index above 50 and a significant amount of crystalline silica as determined by X-ray refraction sufficient. 14. Microspheres according to item 12 or 13, characterized in that they have a SiO ₂ Al ₂ O 3 molar ratio of about 1 to 2 and have been obtained by calcining microspheres of high purity kyanite at a temperature and for a time sufficient to form of microspheres with a mullite index above 45 and a significant amount of crystalline silica sufficient. 15. Microspheres according to item 12 or 13, characterized in that they have a SiO ₂ / Al ₂ O ₃ molar ratio of less than 2 and have been obtained by calcining microspheres which are calcined from a mixture of high-purity kaolin clay and a small proportion of high-purity hydrated alumina, at a temperature and for a time sufficient to form crystalline mullite, crystalline silica and crystalline alumina. 16. Microspheres according to any one of items 12 to 1.6, characterized in that they have an EAI value of 0.5% / sec. or less. 17. A process for the preparation of shaped bodies based on alumina-silica, which are suitable as a contact material for the removal of metals and carbonaceous contaminants from hydrocarbon feedstocks, characterized in that a mineral material which is thermally convertible into mullite and free silica, with a volatile binder is compounded into a mass, are formed from this mass molded body, that then these bodies are calcined for a time and at a temperature sufficient for the conversion of substantially all silica in mullite and crystalline silica, and that these bodies without Leaching of silica or alumina and without grinding or other change in shape of the body can be obtained. 18. The method according to item 17, characterized in that the mass is free from unreacted carbonaceous materials that would form cavities when calcining the body. 19. The method according to item 17 or 18, characterized in that the mineral material is kaolin clay. 20. Method according to item 17 or 18, characterized in that the mineral material is a mixture of kaolin clay and aluminum oxide. 21. The method according to item 17 or 18, characterized in that the mineral material is kyanite. 22. The method according to any one of items 17 to 21, characterized in that the mass is calcined in air at a temperature above 1260 ° C. ' Use of molded macroporous bodies according to any one of items 1 to 16 as a contact material for removing metals and carbonaceous contaminants from a batch of petroleum hydrocarbon feedstocks having a substantial content of Conradson coal and metals, including vanadium and nickel by contacting said feedstock in a Decarbonisier- and Entmetallisier zone with the shaped bodies with low Mikroaktivitätzum catalytic cracking at low load (severity), including a temperature of at least 482 ⁰ C, for a a substantial thermal cracking avoiding time on This treatment involves separating the shaped bodies from the decarboxylated volatilized hydrocarbon fraction with a lower content of Conradsön coal and metals than the feedstock, lowering the temperature of the fraction with respect to the feed For example, by reducing the temperature of the fraction to a level below which substantial thermal cracking would occur, treating the shaped bodies by contact with air at elevated temperature in a separate heating zone to remove combustible deposits from the solid and heating the shaped bodies and returning at least a portion of the shaped bodies from the heating zone to the decarburization and demetallation zone to further decarburize and demetallize the feedstock. 24. Use according to item 23, characterized in that at least periodically an additional part of the shaped bodies is withdrawn from the heating zone and with a solution of a mineral acid for the extraction of nickel and vanadium, without substantial co-extraction of alumina from the formed bodies and without appreciable change the size and hardness of which are brought into contact and at least part of the thus extracted shaped bodies is returned to the heating zone for subsequent reintroduction into the decarburizing and demetallizing zone. Use according to item 23, characterized in that the shaped body is in the form of vortex-capable microspheres and treatment takes place in a riser. 26. Use according to item 23, characterized in that the acid is sulfuric acid. 27. Use according to item 23, characterized in that vanadium and nickel are extracted at elevated temperature. ' Use according to item 23, characterized in that the acid is sulfuric acid which additionally contains monoperoxy sulfuric acid for oxidizing the vanadium to the V ⁺ -5 stage and the vanadium is recovered from the extract by liquid ion exchange or filling. 29. Use according to item 23, characterized in that the acid is hydrochloric acid. 30. Use according to item 23, characterized in that at least 80% of the nickel and at least 80% of the vanadium are extracted. 31. Use according to item 23, characterized in that the nickel and the vanadium are extracted with the solution of the mineral acid, without any other pre-treatment to facilitate the extraction than the burning in air to remove the charcoal and to oxidize the vanadium in the pentavalent valence state. Use according to item 23, characterized in that the shaped bodies as contact material are separated from the acid extract by filtration or the like, and the filtrate has a pH in the range of 0.3 to 1. 33. Use according to item 23, characterized in that essentially all vanadium present in the shaped bodies removed by extraction of vanadium and nickel with a mineral acid is converted into pentavalent vanadium either before, during or after the extraction with the acid , For this 7. pages tables Field of application of the invention The invention relates to shaped macroporous bodies. Among other things, this invention relates to the use of these shaped bodies as the essential non-catalytic contact material in the process of improving petroleum feedstocks contaminated with Conradso.n coal residues and metal contaminants, e.g. Residues or heavy crude oils, according to the technical innovation known in the petroleum industry as "Asphalt Residual Treatment" or "ART" process. This process is described in the literature as "selective vaporization." In particular, this embodiment of the invention relates to the enhancement of reduced formation of agglomerates from the contact material during use.The invention further relates to the improvement of the ART process, which is incorporated herein by reference to direct acid leaching of the metals deposited on the spent contact material and recycling the leached contact material to the ART unit with optional recovery of one or more metals from the acid extraction process. Characteristic of the known technical solutions The "Asphalt Residual Treating" (ART) process is a decarbonation and demetallization process developed for the treatment of residues and heavy crude oils for the purpose of contaminant contamination removal.The process has been described in numerous publications, entitled "(" The ART Process Offers Increased Refinery Flexibility "by RP Haseltine et al., Presented at the NPRA conference in San Francisco in 1983. Further reference is made to Bartholic's US Patent 4,263,128, which is a non-catalytic, technological innovation to remove contaminant contaminants and typically removes over 95% of the metals, substantially all asphaltenes, and 30 to 50% of the sulfur and nitrogen from the residual oil to maintain the hydrogen content in the feedstock. This leads to a large improvement in cost efficiency due to the formation of small amounts of unwanted by-products and the consumption of lower energy than competing processes. The ART process also promotes the following conversion steps in the treatment of residual oils, which is carried out in conventional falling-stream co-pulsing plants. The ART method utilizes a solid particulate contact material which selectively vaporizes the valuable low molecular weight and hydrogen rich constituents of the feed. The contact material is essentially catalytically inert and results in little cracking, if any, provided that the process is carried out under selected conditions of temperature, time and partial pressure. Heavy metals deposit on the contact material and are removed. High molecular weight asphaltenes also deposit on the contact material, and some of the asphaltenes are converted to lighter products. The ART method is suitable to be carried out under continuous heat balance in a plant consisting of a contact zone, a burner and a stock of circulated flowable contact material. The feedstock is contacted with particles of the hot swirlable contact material for a short residence time in the contactor. In the contact zone, the lighter components of the feed are evaporated; the asphaltenes and the high molecular compounds containing metal, sulfur and nitrogen impurities are deposited on the particles of the contact material. The invariably present metals include vanadium and nickel. Part of the asphaltenes and high molecular compounds are thermally cracked to form lighter components and coke. The metals present as well as some of the sulfur and nitrogen bonded components in the unvaporized product are retained by the particles of contact material. At the exit of the contact zone, the oil vapors are rapidly separated from the Kontkt material and then immediately cooled to a beginning